Learning about plants

1) How to Identify Plants
2) How to Use a Botanical Key

3) How to Photograph Plants

4) When Are the Best Wildflower Times?
5) Guided Wildflower Walks
6) Picking and Collecting Wildflowers
7) Wildflower Websites, Hotlines, Education,
     Conferences, etc.
8) Plant Books & App for the Four Corners States
9) Native Plants Online Discussion Groups


1) How to identify plants: An unhurried pace, a discerning eye, a number of good field guides, and a huge dose of self-doubt are good starts toward identifying plants.  Browsing through field guides at home and taking wildflower walks with someone who knows plants are further invaluable methods for learning about plants.  Join your local native plant society, attend their workshops, and go on their field trips. Have patience and pleasure in learning.

To identify a plant with some degree of certainty one needs the plant in hand, a magnifying glass, a detailed field guide, and experience. 

Using botanical keys to ID a plant is quite a daunting intellectual task, because most good keys contain many technical botanical terms that require a good deal of time to master and most keys are fraught with unnecessary complexities, mistakes in parallelism, inattentiveness to precision wording, etc. (See below.) There are, however, several other kinds of keys: 1) Characteristics keys which ask you about prominent characteristics of your mystery plant and then search a database for all plants that have those characteristics: color of flower? date found? elevation? etc. See the opening page of this website for "Select Plant Characteristics". 2) Snap a photo type keys which compare your photo with those in its database. The problem with this type of key is that you learn nothing more than a name. Your brain is completely removed from the keying process and all you get is a name.

For many years I identified a plant as best I could using non-technical photo books. Eventually I found that I often was close but not exact in identifying the species, so after identifying a plant in photo books, I looked for that plant in technical botanical keys and then worked backwards through the keys in these technical books to learn how keys work and to learn botanical terminology. 

This gradual process of getting serious suited me fine; it may work for you or you may want to take college botany classes and plunge in more quickly. 

Perhaps you do not want to take the time to get to know plants this intimately.  You may find that you are satisfied with knowing the family a plant is in or maybe the genus but not the species. Do what is comfortable for you, but don't limit yourself. Just because scientific names seem complex and a burden to you now, it does not mean that they will be that way in the future.  Keep yourself open to learning.

You should, though, keep in mind that if you do not use a detailed professional botanical key the chances are quite high that you will misidentify your mystery plant. So I recommend that if you want to correctly identify plants, you be sure to check your ID in a professional flora such as one of those listed below. Start your process of identification by using whatever wildflower photograph books you have, make your best guess at the identity of your plant, and then look up that name in the Index of one of the complete floras listed below. Read through the description of your plant and see if all the details fit.

A word or two about common names: As indicated elsewhere in this website, common names for plants are not standardized: the same common name is often used for different plants, common names vary from person to person and place to place, many plants have no common name, and in almost all instances we do not know who gave the name, why or when they gave it, or exactly what plant they gave it to.  You can use common names - even ones you make up - to help you remember a plant but that won't help you in discussing these plants with other people  --  or learning from these people or their books.  

Scientific names, on the other hand, allow you to talk about a plant with anyone in the world because the names are the same world-wide.

Plants are highly variable and not subject to easy, perfectly clear descriptions, so it is always necessary to compare keys and descriptions in several floras. Among others, I use the following books for identifying plants in the Four Corners states of Colorado, New Mexico, Arizona, and Utah. Also see below for more recommended books.

Stanley Welsh's excellent A Utah Flora.  Welsh's book is excellent for anyone on the West Slope of Colorado, all of Utah, and all of the Four Corners region. Welsh's book contains plant keys and invaluable complete descriptions which give you measurements and characteristics of all the parts of a plant. I often find that Welsh's keys, descriptions, and very frank and informed notes are the most accurate and perceptive. A Utah Flora 5th edition was published in 2016 but the price of it and even older editions is often over $100. However, the Biodiversity Library has published the 1987 first edition online and it is free and well worth using.

The superb 8 volume Intermountain Flora gives botanical keys, detailed descriptions, and large drawings of all plants.  Intermountain Flora ranks up there with A Utah Flora as my favorite for the Four Corners states -- and all states between the Rockies and Sierras.

Weber and Wittman's Colorado Flora 4th edition, 2012 (Western and Eastern slope volumes) is a paperback field guide that fits into cargo pants pockets. The flora contains keys and many drawings, but overall the flora is far too needlessly complex, convoluted, and full of jargon. The authors should have examined all keys for parallel and accurate phrasing. Wording such as "larger than" "relatively thin", "plants sometimes small" needs to be replaced with precise numbers; 30 cm tall; .1 vs .3 mm thick; .3-1.5 m tall. Even after many editions over the past decades, there are still incorrect leads, i.e., places where the key points us to 12a. but should have pointed us to 16a. Despite these and other significant problems, Colorado Flora does squeeze an amazing amount of information into a small volume and should be used by anyone trying to identify the flora of Colorado. Weber died in 2020 and it does not appear that there will be further editions of this important flora.

Review of Jennifer Ackerfield's Flora of Colorado

The paragraphs below discuss some of the problems in Flora of Colorado. Click for a list of species included in the Flora of Colorado that do not occur in Colorado, erroneous reports of Colorado species, a list of several hundred species omitted from the Flora of Colorado, etc.

I offer the following review of Flora of Colorado so that people can use the positive aspects of the Flora and can avoid relying on aspects of the Flora which are inaccurate. I hope the details below will assist in improving future editions of Flora of Colorado and in the writing of floras in other states.

I sent this review to both Dr. Jennifer Ackerfield and to the publisher, the Botanical Research Institute of Texas, for their comments and corrections. Neither replied. I also sent early versions of this review to ten amateur and professional botanists around Colorado for their suggestions which I used to improve the review.

Botany is a continually evolving, complex science and since no botanist has expertise in every family, every genus, or every species, floras really need to be a team effort. If a flora is authored by one botanist, that botanist should continually strive to present other current views of the flora and should frequently consult with various botanical experts; otherwise we will be presented with a personal and limited view rather than a consensus scientific view.

Dr. Jennifer Ackerfield tells us that her Flora of Colorado came into existence because her students had trouble understanding Weber and Wittmann’s Colorado Flora. Dr. Ackerfield is to be congratulated for expending an enormous amount of time and effort in producing her Flora of Colorado, which takes a step above Colorado Flora by having range maps, species descriptions, keys that utilize genetic information, and photographs.

Flora of Colorado avoids some of the problems of Colorado Flora, but it has some of the same problems and adds in a number more. Many of the problems listed below would have been avoided had a number of botanists authored it.

1) Thousands of dots on the range maps represent misidentified herbarium specimens. 2) Hundreds of Colorado taxa have been omitted. 3) Taxa that have no verified collections in Colorado have been included. 4) Subspecies and varieties are indicated for some species but omitted for others that do have recognized lower ranks. 5) There are a significant number of changes in nomenclature from that of the first edition and from that which is widely accepted. 6) Species are lumped together (or split apart) often with no reference for such taxonomic decisions. 7) Species descriptions need much more attention. 8) The Angiosperm Phylogeny Group (APG IV) is sometimes followed, sometimes not.

These problems really matter because some, such as leaving out hundreds of Colorado taxa, make it impossible to correctly key a number of plants; some, such as indicating that a taxon is present in a county when it actually is not, affect whether a taxon needs protection and how money is spent; and some, such as splitting apart species or lumping them together contrary to widely accepted taxonomy, make it difficult or impossible to relate the flora of Colorado to that of even nearby states which have a far more widely accepted taxonomy.

Following are some details. At the end of this review you will find a list of hundreds of omissions and erroneous reports.

1) The dot range maps contain the most noticeable errors. Page 14 of Flora of Colorado indicates that the dots represent locations of taxa in Colorado. I wish that were true, but as Dr. Ackerfield herself would tell you, that is not true.

We are told on the opening page of Flora of Colorado that in Ackerfield's herbarium research at her alma mater of Colorado State University she found that plant specimen "misidentifications were quite common". Surveys show that herbaria world-wide have from 5% to 40% misidentified specimens. Dots on the Flora range maps were based on the 750,000 Colorado specimens in various herbaria and listed on-line on SEINet, which displays data provided to it by dozens of herbaria. SEINet makes no claim for the authenticity of its entries and indicates, "the data are made available 'as is' ".

No one could possibly verify the accuracy of identifications of these 750,000 specimens. Identifications would have to be done by each herbarium for its collections. Since no one has verified the accurate identification of the 750,000 specimens, the range maps have numerous dots for misidentified specimens. If we take just 5% of 750,000 as misidentified, that means that at least 37,000 dots on the range maps are for misidentified specimens. The dots should not be there and are misleading.

One solution to the misidentified taxa shown in dot maps would be to indicate that verification of the accuracy of 750,000 specimen identifications is not presently possible and the dots should be seen as representing general distributions with no intent of showing county records. An alternate solution would be to avoid using the dots and instead to provide the traditional county listings similar to those used in almost all other floras in the U.S., including the first edition of Flora of Colorado.

The paragraphs below briefly list some of the other problems of Flora of Colorado. See the end of this review for details.

2) Hundreds of plants that have verified collection records have mistakenly been omitted from Flora of Colorado.

3) Flora of Colorado includes species not found in Colorado.

4) Subspecies and varieties are indicated for some species but they are omitted for others that do have verified subspecies or varieties.

5) The most common complaint that people voice about botany is that changes seem to be constant. Flora of Colorado gives much fuel for this complaint, even in the changes from the first edition to the second. For example,

A) Hundreds of county records shown in the first edition (without supporting evidence for their existence) are deleted from the second.
B) In the first edition Cirsium clavatum is described in three times as much detail as any other Cirsium, yet in the second edition, Cirsium clavatum does not even exist and it is implied that C. clavatum is now C. griseum which previously had been included in C. clavatum.
C) In the pre-publication version of the first edition Packera mancosana was said to be a variety of P. werneriifolia.
This was changed in the first edition and P. mancosana was said to be the same as P. werneriifolia.
This was changed in the “Errata” sheet that accompanied the second printing of the first edition and P. mancosana was said to be a distinct species.
This was changed in the second edition and P. mancosana was once again said to be the same as P. werneriifolia BUT P. werneriifolia was split in two (P. werneriifolia and a new species, P. saxosa).
D) The first edition of Flora of Colorado lists nine species of Mertensia (Bluebells); the second lists twenty-two.

6) Species are lumped together (or split apart) very often with no references for such taxonomic decisions even though most other floras (including the authoritative Flora of North America) do not agree with these splits and lumps. A truly scientific approach to a flora would have a central part of its mission to inform readers about complexities and disagreements. Weber and Wittmann’s Colorado Flora often disagrees with the FNA, but almost always indicates that there is disagreement.

7) Species descriptions need more attention: Some aspects of the descriptions are nicely done, for instance in that they commonly provide precise measurements. More attention should have been given to making sure that similar species were described with exactly the same details. Check this out yourself by comparing species that you consider similar.

8) Although it is stated on page 14 of Flora of Colorado that its taxonomy regarding family/genus relationships follows APG IV (the taxonomy based on the work of the Angiosperm Phylogeny Group), it does not; there are departures. All that was needed was a statement such as, "With just a few exceptions, this Flora adheres to APG IV".

There are a variety of other problems in Flora of Colorado, but I will list just several different kinds that are particularly telling:

Botanical research continually gives us new information and inevitably errors in the text of floras come to light. A Flora of Colorado website could keep us up-to-date. There is no such website for the Flora of Colorado, even though it has been repeatedly requested.

The authoritative Flora of the Four Corners Region apparently was not consulted, for it is not mentioned in the “References” and a significant number of its taxa records from Colorado are not included in Flora of Colorado.

William Weber devoted himself to the flora of Colorado for 80 years and he produced numerous editions of his Colorado Flora which were carried into the field by thousands of professionals and amateurs. Weber had a world-wide reputation as a plant scientist and taxonomist, yet he is not mentioned in Ackerfield’s Flora of Colorado.

Ackerfield’s Flora is a complex work that required dedication to produce. Her Flora has significant problems that should be corrected, but it is still essential to use in order to understand the flora of Colorado and we should be thankful that Dr. Ackerfield wrote it. I frequently consult Flora of Colorado, but I always compare it to Weber’s Colorado Flora, Harrington’s Manual of the Plants of Colorado, Heil and O’Kane’s Flora of the Four Corner’s Region, Welsh’s A Utah Flora, Allred’s Flora Neomexicana III, Cronquist et al. Intermountain Flora, and the Flora of North America. By making these comparisons I have a better chance of identifying taxa correctly and I certainly learn much more. _______________________________________________________________
A number of the comments in this review of Flora of Colorado apply to the first edition as well as the second edition. A number of the comments were offered before and after the first edition was published.

Many of the taxonomic details cited in this review are from a list of hundreds of problems found by Dr. John Kartesz as he reviewed the second edition of Flora of Colorado for taxonomic details to include in his 50 year project of producing a county by county list of all taxa in the U.S. and Canada. See .

To benefit the Colorado botanical community, Dr. Kartesz has been kind enough to provide the entire list.

Click here for the list of omissions, erroneous reports, and other problems within Flora of Colorado.

Dr. Kartesz welcomes all comments:

Flora Neomexicana III 2020 second edition, 2 volumes, by Kelly Allred has good keys and descriptions with many excellent drawings by DeWitt Ivey. A number of excellent botanists contributed to this flora. It is a complete flora of New Mexico, but it is also of use in the other Four Corners states and in much of the West.

Flora of the Four Corners Region is a complete guide to the plants of all the lands that drain into the San Juan River (much of the area covered in this website), from the Continental Divide at Wolf Creek Pass to the semi-desert at Lake Powell. Eleven years of field work and the assistance of over 60 botanists produced a botanical guide with keys, complete descriptions, several hundred line drawings, and many excellent photographs. The years of field work on this botanical work uncovered 1,700 county records, 42 state records, and 17 new species.

For Arizona, the Field Guide to Forest and Mountain Plants of Northern Arizona is a very good botanical key. It is clear that the Guide was produced by really good field botanists who are also very good teachers. There are excellent comparisons with similar species, succinct and nicely phrased keys, line drawings, etc. Every time I turn to this Guide I find it accurate and refreshing.

For other information about the flora of Arizona see Canotia.

The other superb volumes to look at for the flora of the Four Corners states (and all of the United States and Canada) are the dozens of volumes on all plants of North America. The Flora of North America plant descriptions and keys for identifying plants are online free

Tools of the trade:

Hand lens: To determine the exact species almost always requires that you look at small (and very beautiful) details of the plant.  For years I used my unaided eyes to try to see and appreciate these details, but eventually I realized that I could not make a correct species identification because I could not see the necessary details. 

I bought a 10 power hand lens (a jeweler's loupe) and that allowed me to see a whole new world of detail. Even if you never use the lens for keying a plant and determining its exact identification, it is worth buying a lens because it opens up a world of beauty that you cannot see with your unaided eye. 

You can buy a hand lens for $5 but I find the $35 Bausch and Lomb or the Belomo triplet well worth the extra dollars. See the second box from the bottom of my "Links" page.

Looking through a hand lens is comparable to dropping below the surface of the water with snorkel gear and discovering a whole new world that was so close and so unseen. 

I am in the field many, many days and my hand lens is always around my neck  --  on the beautifully beaded lanyard my wife made for me.

Microscope: Of course there is always another level of magnification.  My wife bought me a microscope and I can now swim even more deeply below the surface.

Other very valuable tools for identifying flowers:

1) Carry a notebook and pen for making field notes and writing down your questions.
2) Buy a good plant terminology book; I use Plant Identification Terminology by Harris and Harris.  This book is in dictionary format with hundreds of illustrations. I find it absolutely indispensable.
3) Use the web: Do a Google image search.  Use such invaluable websites as BONAP, Flora of North America, California Flora, and Forestry Images
4) Take photos and share your questions about them with wildflower friends who know more than you do.  (Feel free to email your mystery plant photos to me.)

After a while one learns the shape and color of plants and their typical habitats and one can identify many plants from a distance, just as we can identify friends from a distance by their mannerisms, their posture, their walk.  To get to this level of familiarity requires the desire to learn, then time and patience and study.

To determine the exact species, one often needs very particular characteristics.  Sometime one needs to note a number of different characteristics through the growing season.  Sometime one needs to see the flower and seed.  Sometime one needs to see the root.  Sometime you just won't find the details you need to make a precise identification.  You may learn that your plant is a Rosaceae (Rose Family) and that's it.  Perhaps you'll learn the genus but not the species.  Maybe this will be frustrating, but for sure you will be building your botanical knowledge and enjoying the beauty of the plant world.  And bit by bit your ability to identify will grow.

Getting precise about plants is accomplished by noting key plant characteristics.  All detailed botanical texts with keys use such characteristics to lead you through a series of either-or questions in order to identify plants by a process of inclusion or elimination: Is the plant woody or herbaceous? Is it a vine? Is it aquatic?  Each time you answer a question you eliminate some plants and move on to consider others. (See #2 below for more details about how to use a botanical key.)

If you are in the field and do not have a detailed botanical key with you, take a number of pictures of different parts of the plant and then make notes about the plant's characteristics. 

Pay special attention to:
the flower color, shape, and size;
the height and shape of the plant;
the hairiness of various parts including both sides of the leaves;
the plant's habitat and elevation;
the leaf shape, size, color, number, and distribution (basal? along the stem?);
and whether the plant appears to be an annual or perennial.

There are many more factors to notice:

Date, geographic location, habitat, and vegetation zone. 
Woody or herbaceous.  
Height, width, and shape.  
Are plants solitary or numerous?  
Are plants scattered (probably indicating that they reproduce by seed) or close-growing (reproduce from roots). 
Flower location (at top, in leaf axils...), pattern (in a spike, umbel...), and number of flower stalks. 
Structure of flower: stamens, pistils, bracts....
Number and size of leaves both at the base of the plant and along the main stalk, manner of leaf attachment to main stalk (is leaf stemless, does it wrap the stalk...), opposite each other or alternating along stalk, shape of leaf (long, symmetrical, smooth edged, divided...).  
Color of stems, stalks, and leaves (upper and underside). 
Prominence, pattern, and color of leaf veins. 
Are leaf, stalk, and other plant parts hairy, smooth, shiny, spotted? 
Are there streaks, thorns, wings, galls? 
Seed/berry characteristics (shape, color, texture). 
Smell of flower and plant parts. 
Other significant characteristics: does the plant stand straight, arch, or creep along the ground? What is its fall color? Is it browsed by animals?
What plants are found nearby?

These details will seem overwhelming to some, but to others they bring the pleasure of learning about the incredible variety within the plant world and the pleasure of sharing this joy with friends.

Many states offer classes in wildflower identification.  In Colorado, the Native Plant Master program is sponsored by Colorado State University Cooperative Extension. The field-based courses are held on public lands and focus on plant identification with an emphasis on scientific names and families, ecology, landscaping, ethnobotany, and other human uses. 

Feel free to email me anytime with your plant questions.  If you need help in identifying a plant, send me some photos and details about the plant; I'll see if I can help.

2) How to use a botanical key:

Enjoying the beauty of plants and observing their characteristics is a great pleasure. The more we observe, the more we understand and enjoy. Step by step we get into the complexities. Certainly one of the complexities is precise identification of the species, but this identification can only be achieved by mastering the use of detailed botanical keys. I find that there are two very helpful, enjoyable, and relatively painless ways of learning to use botanical keys:

1) Go on field trips with your local native plant society. Watch, listen, and ask questions. Never be shy. Never be intimidated. You will always find very sharing and gracious folks willing to assist you.

2) On your own, select a plant whose species identity you are positive about, for instance, Taraxacum officinale (Dandelion). Find that plant in the botanical key you own and then work backwards through the key to see how the key arrived at Taraxacum officinale. Be sure you understand all the steps and all the terms.

As mentioned above, an unhurried pace, a discerning eye, a number of good field guides, and a huge dose of self-doubt are necessary for identifying plants. If you want to identify the exact species, you will need to use botanical keys developed over the centuries by devoted botanists who gave thousands of hours of their time to distinguishing one species from another.

Most of us enjoy the beauty of flowers; few of us have the interest or patience necessary for keying. If you would like to try your brain at it, here are some detailed suggestions. (Also see Plant Names, especially the section on scientific names.)

First and foremost, don't expect to move easily through the keys and quickly identify a plant. As is true of most worthy endeavors, there is much to learn and many wrong turns along the way -- and great rewards.

Not all keys are created equal. Some botanical keys are easier to follow than others, so when you get stuck in one book, turn to another for assistance. Use a glossary. In the Four Corners states we are fortunate to have a number of botanical keys to examine. We can see that there are not only differences in the ease of using keys in various books, but also that there are differences in the accuracy of the descriptions of the plants. Some botanists are much better at this than others. Writing the keys requires the utmost attentions to detail and the ability to state the details in the most precise language.

Also note that 1) Not all keys in a field guide are written by the author of the field guide. Some keys are so good that they are copied by many authors. 2) Not all the keys in a field guide are of the same quality.

There are many kinds of botanical books. In the following discussion, which elaborates on some of the subjects discussed above, we will not be concerned with coffee table wildflower books that have several dozen color photographs with brief descriptions of plants arranged by flower color. These can be very good books to introduce us to the beauty of plants and get us interested in knowing more precise details. But below we will be discussing the complexities of two other kinds of detailed botanical texts that allow you to precisely identify a species:

1) The complete description flora is a large format book that gives detailed keys that allow you to identify all plants of the region and it provides a complete description of each family, genus, and species.

2) The field guide flora is often in a pocket-sized format and contains keys that allow you to identify all plants of the region. There are usually very brief family and genus descriptions and only enough species details to allow you to distinguish between species.

Some of these expert floras have color photographs and/or line drawings.

Keys in detailed floras assume several things:

1) Keys assume that we are looking at a fully developed plant.

2) Keys assume that we use a 10x hand lens to observe minute characteristics, for instance, not just that a plant has hairs, but what shape the hairs have, how they are oriented, etc.

3) Keys assume that we are familiar with botanical terminology. To assist us, the books give us a glossary of all the terms the authors uses.

How is a key structured?

Almost all professional keys are dichotomous (from the Greek, "cut in two parts"). The two part choices may be written in a number of different ways:
1a. and 1b.
1 and 1'
1 and 1.
1 and 1
1 and --

However the two choices are  written, the key presents us with a series of questions:

1a. Plants short ...2
1b. Plants tall ......7

The "2" at the end of 1a. tells us that if we have a short plant, our next step in the treasure hunt is to go to the choices listed in 2 and that will lead us to 3, 4, 5, and 6, all of which deal with short plants.

All the choices from 7 onward deal with tall plants.

Choice 2 might indicate:
2a. Flowers yellow................3
2b. Flowers pink or purple.....5

I hope you asked, "What does the key mean by "short" and "tall"? Sometimes such vague words are good enough to separate species, but too often they are not, and the keys fail us by not providing precise measurements:

1a. Plants 3-14 cm...2
1b. Plants 10-30 cm...7

Now I hope you asked, "What if the plant I am trying to identify is 12 cm? It could be 1a. or 1b." Yes, that can be a sticking point, but a good key would have given you more details:

1a. Plants 3-14 cm, flowers in terminal clusters, alpine...2
1b. Plants 10-30 cm, flowers in axillary clusters, montane...7

(Notice, by the way, that 1a. and 1b. are expressed in the same terms [Plants 3-14 cm vs. Plants 10-30 cm] and these terms are arranged in the same order [height, flower position, location]. Even in the best of floras, one is commonly frustrated because authors do not use parallel construction.)

Following are some basic points about how to key plants:

1) Read through all introductory material at the beginning of the book and at the beginning of each key. Keys begin with information about the family and some of that information is vital to keying but is not repeated in the genus information. You also need to read all the information given in the genus description since that information is not always repeated for each species within that genus. For instance, when reading the compete description of a species you may want to know about the kind of hairs on the leaves but not be able to find that in the complete description of that species. Go back to the genus and family descriptions and you may find it stated that all species in that genus or family have stellate hairs. The author sees no point in mentioning those leaf hairs again in the description of each species.

2) Next, read through all information given in each couplet of choices. Each choice within the couplet gives characteristics in order of importance.

In the example several paragraphs above,

1a. Plants 3-14 cm, flowers in terminal clusters, alpine
1b. Plants 10-30 cm, flowers in axillary clusters, montane

the height of the plants is the most important characteristic.

3) Note that the entries under 1a., 1b., 5a., 5b., etc. do not give us complete descriptions of a plant; they only only give us what the author thinks is sufficient detail for distinguishing between plants (or groups of plants).

If your book does not give complete descriptions of plants but only gives the steps, 1a., 5b., etc., you can still compile a list of basic descriptive details about the plant by writing down all the details given in the steps that led you to the correct ID. For instance, if your plant was found at step 26a. write down the details given there and then work backwards to 20b., 14a., 4b., and 1a. You can see how valuable numbers listed in [] are when you try to work backwards. See 5) below for an explanation of []

4) When using a key, you may find yourself confused because of the author's word choice. We tend to blame ourselves when we cannot figure things out, so I have the discussion below to let you know that in a number of cases your confusion is not of your own making. It is the fault of the key.

The dichotomous key should be expressed in very carefully chosen words in parallel form:


1a. Plants 3-14 cm, flowers in terminal clusters, alpine
1b. Plants 10-30 cm, flowers in axillary clusters, montane


1a. Plants 3-14 cm, flowers in terminal clusters, alpine
1b. Main plant stems of the plants 100-300 mm, 8,000-9,500 feet, inflorescences usually found growing from axils.

This lack of parallelism causes confusion and is often compounded by poor word choice. Following are two examples from the key for Lupinus in Colorado Flora: Western Slope 4th edition:

4a. [1] Dwarf, forming low, spreading clumps; the inflorescence shorter than the leaves. Lupinus lepidus
4b. Tall, usually erect; the inflorescence exceeding the leaves.....5

4a. and 4b. are expressed in fairly parallel structure: dwarf vs. tall; spreading vs. erect; and inflorescence shorter than the leaves vs. inflorescence exceeding the leaves.

Could the parallelism be better, i.e., could the choices be more clearly expressed? Yes. Compare the following with the previous. Do you feel the difference in the clarity?

4a. [1] Dwarf, spreading; inflorescence included within the leaves. Lupinus lepidus
4b. Tall, erect; inflorescence exceeding the leaves.....5

"Inflorescence shorter [or taller] than the leaves" could be interpreted in several ways: it could mean that if we measure the length of the inflorescence (say, 4 cm) we will find that the leaves are longer than 4 cm. Or it could mean that the inflorescence is so short that there are leaves above it, i.e., the inflorescence is surpassed by the leaves. The latter is what the author meant to say.

Examine the next step in the same Colorado Flora: Western Slope key for Lupinus:

5a. Banners reflexing at or near the midpoint, leaving a relatively wide gap above the wings; longest petioles near the base, the upper ones often much reduced....(6)

5b. Banners reflexing above the midpoint, and the ventral groove clasping enough of the wings so the tip of the banner leaves a small opening between the wing tip and the banner tip; leaves mostly short-petioled, occasionally somewhat longer below...(12)

I struggled for a very long time to understand what 5a. and 5b. meant. I asked other good field botanists and they too struggled. Only after I read several other floras did I figure out what 5a. and 5b. mean, and now I can rewrite 5a. and 5b.:

5a. Banner reflexed at or near its midpoint; leaf petioles longest near base of plant, upper petioles often much reduced.....(6)

5b. Banner reflexed above its midpoint; leaf petioles occasionally slightly longer near base of plant, almost all leaves short-petioled...(12)

Notice the simple but really clarifying change from "the midpoint" to "its midpoint" and the removal of the information about a "gap" and "ventral groove" both of which are completely clear and accurate (once you know what they mean!!), but are nothing but fog the first 30 times you read the words.

Several keys by other botanists add measurements to make the above description more accurate and more clearly stated:

5a. Banner reflexed at or near its midpoint, approx. 3-6 mm from banner tip....

5b. Banner reflexed above its midpoint, approx. 3 mm or less from banner tip....

We can even shorten this:

5a. Banner reflexed 3-6 mm from its tip....

5b. Banner reflexed less than 3 mm from its tip....

Wow. That is so much better, clearer, more accurate. Yes, we still could have problems with understanding the choices: What is a banner? What is the meaning of reflexed (or recurved, the word several keys use)? What is " mm"? The burden of knowing these points is completely ours to bear. Use the glossary.

One more very important point here: the keys do not even agree with each other on the description of the banner reflex, or on whether you even need to look at the reflex in order to key the genus. One local flora key indicates "reflexed at or near the midpoint" but two other keys indicate "at or below the midpoint". One key indicates "3.5-6 mm below the apex"; another indicates 3-6 mm below the apex". And the Flora Neomexicana III and the Jepson Manual do not key Lupine on the basis of the reflex of the banner but instead on the basis of the calyx shape and hairiness of the various species.

Plants are not easily categorized into 1a. 1b, 2a 2b. They are highly variable, often overlapping in their characteristics. It is, therefore, a very good practice to use several keys. 

I hope it is clear that we are discussing mistakes in botanical keys for one major reason: so that you don't feel that it is always your fault when you cannot understand the key. A great deal of time and care goes into the construction of botanical keys and most of the time these keys are accurate. But in too many instances, the problems are in the key, not in us.

5) In 4a. above, what does the [1] mean? This is a very handy and thoughtful inclusion in keys. Unfortunately few keys use it. The [1] tells us how we got to 4. We were on 1 and made a choice that took us to 4. Why is this so nice to have? Because it very commonly happens that you follow your choices to a dead end. Perhaps you arrive at 54 and the choices you are left with are both wrong for the plant you are trying to identify. Where did you make a mistake prior to 54? How did you get to 54? The [ ] tells you where to backup to in order to check your previous choices.

The [ ] is also very nice to have because it allows you to work backwards through a key to assemble a list of characteristics for the species you identified. It also allows you, once you have identified your mystery plant, to retrace your keying steps to reinforce your knowledge of keying and to learn about the characteristics of other members of the genus.

6) It is important to consult the glossary of the key you are using; the meaning of some terms varies from author to author. In addition, as mentioned above, it is so important to have an illustrated glossary, such as, Plant Identification Terminology by Harris and Harris.

Botanical terms may be confusing, difficult to understand, or subject to several interpretations.

A) Annual, biennial, and perennial.

Early in the keys in a number of families and genera you will be asked if the plant you are trying to identify is an annual, biennial, or perennial:

1a. Annual or biennial..........2
1b. Perennial or some biennials.......8

How does one determine, in the field, whether a plant is annual, biennial, or perennial?

Since there are no quick and easy fool-proof answers to separating the three, it is common to have to choose 1a. and then 1b. and work through both sides of the key to see which leads you to the plant you are identifying. You will then know whether your plant is an annual, biennial, or perennial and you can look at its characteristics to see why it fit the annual or perennial side of the key. In this manner, you gradually build your ability to distinguish annual, from biennial, from perennial.

Increasing the difficulty in distinguishing between annual, biennial, and perennial is that a plant's appearance changes during growth season; an annual in August may look much more like a perennial than it did in April.

Also, of course, biennial and perennial plants do have a first year of growth and they can then appear very similar to annuals.

Following are a few clues about determining whether a plant is annual, biennial, or perennial:

Overall appearance: Perennials and biennials may have last year's dried (or even green) growth still visible. Check the plant closely for dried stems and seeds and the presence of multiple layers of basal leaves.

Life span: An annual sets in its roots, fully develops its stem and flowers, and goes to seed and then dies in one season, sometimes as short as a few weeks. A biennial produces leafy growth in its first year and then flowers and dies in its second year. Perennials live and produce flowers and fruits for three or more years. Remember that these distinctions can blur; weather, genetics, etc. might cause an annual to live for several years or a perennial might die in just two years. Also, it is relatively common to find spring blooming annuals produce seeds which sprout and flower the same fall or early winter when temperature and moisture conditions are just right for it.

Roots: I do not like digging up a plant to look at its roots, but roots are one significant key to separating annual from perennial. You can get a peak at the roots without killing the plant by scrapping some dirt off the top and sides of the roots.

Generally speaking, annuals have far less developed root systems than perennials. Annual roots are fibrous (thin and branched repeatedly). Often I find that annual roots are soft, flexible, light colored, and not at all woody. The outer surface in contact with the soil is smooth and not shredded or bark-like.

Perennials have a much more robust root system with much thicker roots and the branches are also much thicker. The roots are stiff, dark, and commonly woody at the top. The outer surface in contact with the soil is rough, shredded, and bark-like.

Cotyledons: If you get to the plants early enough in the season, you might distinguish between annual and perennial by the presence (annual) or absence (perennial after the first year) of cotyledons.

Base of stems: At ground level an annual stem will look very much like the root just below ground level and very much like the stem just above ground level. They are all soft, flexible, thin, herbaceous.

There often is a clear distinction in these three zones for biennials and especially for perennials with a stiff, woody consistency to the main plant stem at ground level.

Stems: Generally speaking, annuals are shorter, more delicate, and have fewer stems than biennials and perennials. If an annual has multiple stems, these are usually very thin and flexible. There are annuals in our area that do, however, grow thick stems 3-6 feet tall in their one season.

B) Flower color

I find that keys ask about flower color far too infrequently. Much more color information should be included.

Color is omitted for a number of reasons, one not so reasonable: I am convinced that some professional botanists think it is non-scientific to discuss color.

There are, however, a number of good reasons for not basing keys on color:
a) Color tends to fade as the flower ages.
b) Color in some flowers fades after pollination.
c) People perceive flower color differently.
d) A significant number of flowers commonly have different colors in different locations.
e) Sunlight greatly affects our perception of the very light shades of pink and blue, often making them appear white.
f) Botanists who develop the keys work primarily from dried herbarium specimens that do not show the flower's true colors.

C) Basal leaves

There are a number of terms used to describe the density of a plant's leaves at ground level. Some of the terms are used interchangeably; some are used in contrast to one another. They can be confusing.

Basal rosette
Clump or clump forming
Cluster of basal leaves
Tufts or tufted

Send me your questions and suggestions.

3) How to photograph plants:

Following are some of the basics for taking good plant photographs:

Having a camera with a good quality lens 
Having patience and taking your time
Getting down to the level of the plant (often stretched out on your belly)
Looking at the plant from different angles 
Framing your plant on a contrasting background that makes the plant stand out 
Having the proper camera settings 
Carefully looking at all the things you see in your view finder before you press the shutter button 
Pressing the shutter button slowly (Squeeeezing - not punching.  Don't jerk or bounce your finger off the shutter button.)
Knowing your plant   

These and more points are discussed below.

The first thing I did with my digital camera was to learn to use the vast array of menu choices; I sat at my desk reading the manual and shooting hundreds of pictures as I read.  I changed the menus and quick buttons to the settings I thought would be most useful to me; the camera manual tells how to do this.  If you do not read and re-read your manual you will have wasted a good deal of your money and you will not be able to produce quality photos.  You will be on "auto" all the time and will basically have a point and shoot camera.

There are some settings on my camera that I never use.  I do not use saturation, sharpen, etc.  I use Adobe Photoshop for these functions if they are necessary.  (My most common uses of Photoshop for my wildflower photos are cropping, brightening the picture with "levels", and sharpening the picture with "smart sharpen".)

Once you understand the mechanics of your camera, you have many choices:

1) Decide what kind of plant photographs you want to take: Pretty flower pictures?  Detailed identification pictures?  Quick shots to remind yourself of good times and pretty places?  Photos for printing?  Photos for the web? The answer to these questions will determine many things you do with your camera.  Certainly your answers will determine what resolution you shoot at.  If you plan to make some really fine prints, you will want to shoot at the highest resolution possible in TIFF, RAW, or least compressed JPG.  For my web photos I use the highest JPG resolution, i.e., the least compressed.

2) If you really want to show the plant for what it is, you almost always have to get down to its level -- on your belly or on your knees.  You are going to get dusty, dirty, and muddy and you are going to get great photos.  

3) If you are trying to use the photos for identification purposes, you need something in the photo for scale.  A close-up shot of a tiny flower makes the flower look huge.  That often won't help folks identify the plant.

4) If you really want to see the plant for what it is, you need a camera that can focus down to at least an inch or two (mine focuses to one centimeter) and one that gives you complete manual control. 

Wind, super bright sunshine, and dark gray skies are realities of life.  You need to be able to adjust your shutter speed and your shutter opening. 

I almost always shoot on the manual setting and make adjustments for the above changes in nature.  My camera (Panasonic FZ35) allows me to store these settings under "Custom settings" so I do not have to keep punching buttons in the Menu.  I have one group of settings for close-ups of plant parts stored in Custom Setting One and another group of settings for backing off and seeing the entire plant stored in C2.  C3 has settings that are best for landscape shots that show the entire habitat of a plant.

5) I almost never use the LCD monitor to view my photo subjects.  Holding the camera out in front of you with your arms swaying, pretty well guarantees blurred pictures -- or at least photos not as sharp as those you will get holding the camera against your face with arms against your body.  This position gives you great stability.  You make yourself into a stable tripod.

Also, of course, sunlight striking the LCD makes it difficult or impossible to see your subject.

6) Be sure to SLOOOWLY SQUEEEEEEZE the shutter button.  Punching it will also guarantee blur.

7) For close-up shots you will have to use your LCD monitor unless you have a camera that allows you to actually look through the lens with your view finder.  My Panasonic FZ35, similar cameras, and SLRs allow viewing through the lens.

8) There are times when a zoom lens really helps.  I do not like tromping through delicate plants just so I can get the shot I like.  With a zoom, I can stand on the trail and get some pretty nice shots.

9) Setting up your digital camera for each shot can be a real pain.  There are, however, several frustration-saving alternatives: 
     A) Some cameras have memory slots on the menu that allow you to make any changes you want to your settings and then have your camera memorize them so they are available with one click of a button instead of dozens of clicks through your menus.  
     B) Or you can make all the lighting, speed, macro, etc. changes and then not turn off your camera.  The camera will go to sleep after a minute or two (you choose the time in your menu) and a partial press on your shutter button will quickly wake it up with all your settings retained.  
     C) Or you can go into your menu and turn off the "Auto Reset".  Your camera is set to erase all the menu changes you make and return the camera to the factory default settings when you turn off the camera.  Turn off this function and all the setting changes you make will be retained.  At the end of the day, turn this function on and you are back to the factory settings.
     D) You can also change your menus and buttons to those functions you most often use.  This will enable you to adjust your settings much more quickly.

10) When you look through the lens, look at everything in your field of view.  Otherwise you will wind up with someone's foot, a distracting bright spot, an unwanted plant, etc. in the photo. 

Be sure that your plant stands out against the background.  Green plants against a green background don't show up.  Look at the plant from all sides until you find the best background. 

You may want to blur the background by opening your shutter wide and increasing your shutter speed.

11) Sometimes backing off your subject a bit gives you a better picture than being in as close as your camera will allow.  You will get better depth of field.

12) Look at your plant from different angles.  Which angle is best for the kind of picture you want?

13) When you want to focus on a small detail, you will often get the best results using "spot metering".

14) Study your downloaded photos.  Your camera software imbeds all of your camera settings in each picture.  Your computer camera software will tell you all of these settings.

14) The more you know about your plant, the better you will be able to photograph it.  I come back to the same species many times over the years and I find that when I am really familiar with a plant, I get better photos.

Carry an extra set of batteries and an extra memory card.

4) When are the best wildflower times? Wildflower growth is subject to the whims of nature and is not on a human arboretum schedule.  Some wildflower years are spectacular, some sparse.  Because of conditions that favor them, certain species bloom profusely in one year but not another.  As outlined below, many factors influence where and when you should go looking for wildflowers and whether your wildflower hunt will be successful.

"The height of wildflower season" shows us the broadest distribution of the greatest number of flowers.  But many species of flowers will bloom and die before this height and many after it.  Some of these flowers put on magnificent shows, sometimes carpeting huge areas with very few other flowers evident. You won't see this display if you come at the "height of the season".  

Further, in order to find wildflowers during the height of the season (or at any other time) one needs to go to the right places -- and walk.  Viewing wildflowers from a car is like praying to God while watching television.  We still thankfully have some wilderness in the United States and it is in these areas that wildflowers thrive.  When you see photographs of  mountain meadows filled with wildflowers and surrounded by 14,000 foot peaks, you are almost always looking at the result of a hunt on foot.  The mountains, deserts, and prairies in bloom are most appreciated by those who travel afoot.

Having said all this, what can I tell you about where and when you should go looking for wildflowers? 
A) Each flower shown in this site has descriptive material that tells where and when the picture was taken.  You can search this website by date and get a list of plants that might be blooming at the time you plan to be around. 
B) Call National Parks in the area you are going to and ask how their wildflower season is progressing. 
C) And finally there are a number of sections in this website that give some further specific assistance:

Vegetation zones and habitat.
Season of bloom.
Wildflower hotlines.

I hope you enjoy your wildflower search and the joy that wildflower beauty brings.

5) Guided wildflower walksAn online search will lead you to many outfitters and guides who take folks on long, multi-day backcountry horse, hike, and bicycle trips.  None of these, however, focus just on wildflowers. You will also find a number of multi-day wildflower photography trips.  But the intent of these trips is to build your photography skills, not your wildflower identification skills.

Unfortunately, national parks in the Four Corners area have few or no ranger guided wildflower walks. This is the result of massive under-funding of our national parks and misguided priorities.

Check native plant societies for their field trips.

Redwood Llamas has guided trips and rent-a-llama trips through the wildflowers in the San Juan Mountains near Silverton, Colorado.

From June 10 to August 18 the Colorado Trail Foundation has a number of workshops at its 10,600 foot high retreat west of Lake City, Colorado. One week workshops are offered in wildflower identification, painting, hiking, music, climbing. Click for details.

The Durango Seniors Outdoors offers many trips every week of the year and there are special summer wildflower trips.

The July Crested Butte, Colorado, wildflower festival offers many guided walks.

The Rocky Mountain Biological Laboratory (just a few miles from Crested Butte) offers guided wildflower trips through the summer.

The Chihuahuan Desert Native Plants Conservation Initiative annually has guided wildflower trips every weekend of April in southern New Mexico.

6) Picking and collecting wildflowers:  Should we pick wildflowers?  Should we collect wildflowers?  For many reasons, the answer is "No".

It is a tribute to the beauty and appeal of wildflowers that we want to hold them in our hands.  We should remember, though, that a great part of what appeals to us is the beauty of the flower growing wild in its natural surroundings.  Picking a flower and admiring the sheen of its yellow petals is comparable to killing a bird and admiring the iridescence of its feathers.  Do we really need to destroy beauty just to own it for a few hours?  Even the scientific collector does damage: populations of endangered flowers have been made more endangered or exterminated by collectors who felt they just had to own that species.

Here are some specific reasons for not picking or collecting plants or wildflowers:

A) Some of us pick/collect believing that the plant is so abundant that we are not doing any harm.  We are rationalizing to justify our destruction:  

     1) The vast majority of us do not even know the exact species of plant we pick, so we do not know if it is rare, endangered, threatened, or abundant.  
     2) A plant can be abundant in one area, yet be endangered in general. 
     3) If we justify our collecting of flowers or whole plants, we must agree then that everyone can do the same.  Some trails are walked by thousands of people in wildflower season.  Where have all the flowers gone? 
     4) Most people who pick wildflowers would draw a line somewhere.  Most would not pick very dainty orchids that grow only by the ones and twos in secret spots. Perhaps we should be consistent and not pick at all.

B) It is an incontrovertible fact that if we pick a flower or plant we are interfering with natural processes:

     1) We have stopped the plant from reproducing.
     2) We are interfering with the process of growth, decay, and natural selection.
     3) We are interfering with that plant's role in stabilizing and building soil.
     4) We are interfering with the food supply of innumerable critters that eat wild plants and their seeds.

C) We are setting a very poor example for those, especially children, who see us picking.

D) We hold picked flowers in our hands for a few minutes or hours or keep pressed flowers for a few months or years. We all know about throwing out our seashell, rock, wildflower,... collections when we move or clean house.  Unthinking, fleeting, self-gratification is the essence of collecting.

E) It is, as the above points make clear, unthinking and irresponsible to collect.  It is also illegal.  Collecting of anything in national parks and national forests is illegal  --  for the very reasons given above.

What would the world be, once bereft
  Of wet and wildness?  Let them be left,
O let them be left, wildness and wet;
    Long the weeds and the wilderness yet.
                    from "Inversnaid" by Gerard Manley Hopkins


7) Wildflower websites, hotlines, education, conferences, etc.  (Hotlines are seasonal.)

Desert USA online Wildflower Reports (Be sure to explore the entire excellent website.) (760) 767-4684 
Phoenix Desert Botanical Garden 480-481-8120 
Tucson Arizona-Sonora Desert Museum
California Living Desert (619) 340-0435 
Southern California Hotline (818) 768-3533 
National Wildflower and Fall Color Hotline (800) 354-4595
Crested Butte, Colorado, Wildflower Festival
Rocky Mountain Biological Laboratory  
National Wildflower Events Calendar (from Lady Bird Johnson)

8) Bibliography of Wildflower Books, Technical Floras, and Apps
for Colorado, Utah, Arizona, New Mexico, Southwest U.S., and the Rocky Mountains

Some of the books listed below can be purchased from "Exotic Plant Books", a company that donates a portion of purchases to native plant societies.

Also see the websites of the native plant societies of Colorado, New Mexico, Arizona, and Utah for their bookstores.

*All of the works below are valuable, but those marked with an asterisk* are ones I find particularly useful in the field and for this website. Those marked ** are the prime texts that I use in the field and for this website.

Whether you are an armchair wildflower enthusiast, an amateur who likes wandering the wildflower trails, or a wildflower aficionado, you should own as many floras as possible. None have all the answers and it is only by comparing information that you get close to understanding plants. Those folks who are not professionals often shy away from the technical floras. Don't. Use whatever books you are comfortable with and when you are trying to identify a plant, always check your answer in the detailed professional guides.

A word of caution about commonly available wildflower books: Beautiful photographs, neatly printed pages, and nice layout do not a good book make! Before you buy a wildflower book, carefully examine the photographs and information about a plant you are very familiar with to see how accurate the details are. If you find problems, you probably want to avoid that book.

I have looked at dozens of wildflower books and find that most of them are at first glance very appealing. A careful reading of the text has repeatedly shown me numerous errors in the identification of plants and in information about the plant's characteristics, distribution, habitat, etc. I commonly find that several plants are misidentified in these books and even more commonly find that the scientific names of even more plants are outdated. Most publishers of such books have money, not accuracy, as their bottom line.

Examine the books I suggest below and you will see the difference between them and common, popularized wildflower books. But even though the authors of the books listed below have accuracy as their bottom line, no botanist has all the answers and, in fact, you can be assured of significant mistakes in many of the floras listed below. These mistakes occur for a number of reasons:
1) Plants are very difficult to place into exact categories.
2) Editing floras is very difficult and few authors and publishers give the floras the time and expertise necessary to catch errors.
3) Hubris.

Buy a number of floras and compare their keys, photos, drawings, and descriptions. You will quickly see what I mean in the above paragraph. Also note that you will find various floras disagreeing on the descriptions of plants. Unlike birding or such sciences as physics and chemistry, there is little to no standardization in botany: there is no national or international group that sets plant names and there are no standards for plant descriptions. See my discussion above about using botanical keysSee also "Plant Names" on my website.

Bibliography of Botanical Works for the Southwest United States
(Also see discussions about floras above.)

*All of the works below are valuable, but those marked * are ones I find particularly useful in the field and for this website. Those marked ** are the prime texts that I use in the field and for this website.


*Click for "Colorado Rocky Mountain Wildflowers". I made this app for phones and tablets, Apple and Android. The app has several thousand photos of 600 species from the foothills to the alpine zone and covers plants that are found throughout Colorado, in all of the Rockies, and beyond.

The app has thumbnails and enlarged photographs, detailed descriptive information about each plant, interesting tidbits about the plant, range maps, cross references,a glossary, and a fun to use identification key based on facts (is the plant a tree, fern, shrub, or wildflower; what is the color of the flower; what month was it observed; etc.) and plant characteristics (height, shape of leaf, etc.).

The app is designed to be useful for professionals, for amateurs wanting to learn about plants, and even for armchair plant admirers.


Start with the best for most people:
1) Colorado non-fiction book award winner,
Wild at Heart by Janis Huggins. This superb natural history book covers Rocky Mountain high country plants, mammals, and birds. Excellent drawings and photos illustrate the authoritative text. To purchase, email Janis.

2) Peterson Field Guides:
A) Field Guide to Rocky Mountain Wildflowers. Craighead, Craighead, and Davis. An old standard loaded with information not found in other books. This is one of the first flower books I owned and it informed and inspired me. The authors were top notch experts.

B) Southwestern and Texas Wildflowers. Niehaus et al. This Peterson covers 1,500 species at all elevations and makes an excellent companion to the Craighead guide. _____________________________________________________________

Alpine Flower Finder. Wingate and Yeats. Very nice pocket-sized book for beginners.

Alpine Wildflowers of the Rocky Mountains. Duft and Moseley.

*Botanical Latin. William Stearn. THE botanical Latin authority. Pronunciation, grammar, syntax, vocabulary, etc.

Cacti of the Southwest. W. Hubert Earle.

Canyon Country Wildflowers. Damian Fagan.

**Colorado Flora, Western Slope. William A. Weber and Ronald C. Wittmann. (4th edition, 2012.) Detailed keys in a field guide packed with information, glossary, line-drawings, and historical and biographical material. No photographs. Almost everyone (including me) finds this flora difficult and frustrating to use, but it is definitely worth learning to use. Always use it in conjunction with other floras and wildflower photo books. Caution: the names of many species (and even some families) in this flora differ from those accepted by almost all other botanists, but the authors do (almost always) indicate when their plant names differ.

William Weber died in 2020 and his co-author, Ronald Wittmann, has indicated that there are no plans to revise Colorado Flora.

Common Southwestern Native Plants. Jack Carter. Every book that Professor Carter authored is to be treasured.

*Dictionary of Plant Names. William Stearn.

**Dictionary of Word Roots and Combining Forms. Donald Borror. Botanical Latin roots. Concise definitions in a pocket-sized volume.

Edible Native Plants of the Rocky Mountains. Harrington and Matsumura. Harrington was the authority for plants of Colorado through much of the 20th century. Harrington describes plants and gives recipes for plants that he and his wife ate.

*Field Guide to Colorado's Wetland Plants. Culver and Lemly. Excellent guide to identification, ecology, and conservation of wetland plants. Photos, keys, descriptive material.

*Field Guide to Forest and Mountain Plants of Northern Arizona. Springer et al. An excellent book by dedicated teachers and field botanists. Many features found in no other books.

A Field Guide to the Plants of Arizona. Epple and Epple. Very good photos and information.

**Flora of Colorado. Ackerfield. Click to read my review of this flora at the top of this page.

**Flora of the Four Corners Region. Heil and O'Kane. Keys, complete descriptions, drawings, and photographs of 2,300 species of plants found in the Four Corners region, from the alpine above Wolf Creek Pass to the semi-desert at Lake Powell, thus covering much of the same region that this website covers.

Flora of the Four Corners Region is the culmination of a decade of field work by the lead authors and a cadre of volunteers and several years of writing keys and descriptions by dozens of botanical experts. It is worth owning no matter where you live in the mountains and deserts of the southwest, but remember that it has only those plants found in the drainage of the San Juan River and therefore only parts of counties in the Four Corners area are covered. Click for more information.

*Flora Neomexicana II: Glossarium Nominum. Kelly Allred. Meaning of botanical plant names. Excellent.

*Flora Neomexicana III. Kelly Allred and DeWitt Ivey. 2nd edition, 2020. An excellent key to New Mexico flora with Ivey's great line drawings. No photographs. Decades of experience went into making this flora. If you live in New Mexico, southern Colorado, southeast Utah, or eastern Arizona, you will find this flora excellent for your area.

*Flora of North America. This vast, authoritative, 30 volume work in progress will eventually provide keys to and descriptions of over 20,000 North American species. Keys available free online. I often use the Flora of North America website.

Compare the keys and descriptions on the FNA website with any of the other floras mentioned here in my bibliography. The FNA will show you what expert botanists and expert editors can produce. This is a massive and superb effort at cataloging all the flora of North America.

*Flora of the San Juans. Susan Komarek. An excellent key to Four Corners mountain flora. Line drawings and photos. Accurate but non-botanical terminology. The best book for most folks who are interested in determining the exact species without learning complex botanical terminology. This book is now out of print and sold out but used copies are often available online and in book stores.

Flowers of the Southwest Mountains, Flowers of the Southwest Mesas, Flowers of the Southwest Deserts, Shrubs and Trees of the Southwest Uplands, Shrubs and Trees of the Southwest Deserts. Published by the Southwest Parks and Monuments Association. Good introductory text and drawings. I cut my botanical teeth on these volumes and still find them very helpful.

*Guide to Colorado Wildflowers, Volumes 1 and 2.  Revised second edition. G. K. Guennel. Accurate and concise descriptions with water colors and photographs. Out of print but available used. These are two volumes that everyone will profit from.

Handbook of Rocky Mountain Plants.  Nelson. Revised by Roger L. Williams.

Hummingbird Plants of the Southwest. Marcy Scott. Nothing else like it. Very well done.

**Intermountain Flora.  Cronquist et al., 8 volumes. The authority on intermountain flora (from the Sierras to the Rockies). Detailed botanical keys, complete descriptions, exhaustive synonymies, large line drawings of every plant, voluminous information. No photographs. One of the world's flora treasures. Excellent for Utah, and the West Slope of Colorado. Also useful for northern Arizona and northern New Mexico. If you are a serious amateur or professional botanist living anywhere in the West, you will profit from and treasure these volumes.

Land Above the Trees. Zwinger and Willard. Zwinger's line drawings and magical language plus scientifically accurate text makes this book rank among the best.

Land of Enchantment Wildflowers. A Guide to the Plants of New Mexico. Finley and Nieland. Good details and photos of 200 plants.

*Manual of the Plants of Colorado. H. D. Harrington. Excellent, even though dating from 1964. Keys and descriptions of all Colorado plants.

National Audubon Society Guide to Wildflowers, Western Region. Spellenberg.

**Plant Identification Terminology. Harris and Harris. Indispensable for everyone. Illustrated concise definitions of a myriad of botanical terms. I frequently use this book and recommend it above all other books mentioned here.

Pocket Guide to Sagebrush, click for free PDF.

Rocky Mountain Alpine Flowers. This is one of several very nice pack-sized volumes on the flora of the Rocky Mountains.

Rocky Mountain Flower Finder. Wingate. Very nice pocket-sized book for beginners.

Shrubs and Trees of Colorado. Carter. Superb keys, descriptions, drawings, and photographs. Any book by Professor Jack Carter is to be treasured.

Shrubs and Trees of New Mexico. Carter. Even better than the above.

Spring Wildflowers of Utah's Red Rock Desert. Lesica and Fertig. Two experts teamed up to produce a very nice look at southeast Utah. Watch out for several misidentified plants and some awkward and incorrect text.

**A Utah Flora. Stanley Welsh. Excellent for Utah and surrounding states. Excellent keys, descriptions, comments by the master of Utah flora. I often find that Welsh's keys and comments are far better than those found in any other flora. Unfortunately few copies of each of the five editions (5th in 2018) of A Utah Flora were published and, therefore, the price of the flora is usually quite high. Buy a used copy or visit the Biodiversity Library which has published the 1987 first edition online free. It is well worth using.

Wildflowers of the Rocky Mountain Region. This 2018 excellent book from the Denver Botanical Garden describes and shows photographs of about 1,200 plants found throughout the Rockies. Excellent photographs, text, range maps, etc.


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Websites of particular significance for Colorado:
Also see the Links section for an extensive list of online resources for the Four Corners states and beyond.

**Southwest Colorado Wildflowers, Ferns, and Trees


***Biota of North America Program. This is the best, most astounding Internet source of information about plants. Click every link you see on the BONAP website and you will be amazed. You will find county by county records of every plant in the U.S. and Canada, hundreds of thousands of photographs, checklist of all plants with synonyms, and much more. Be sure to go to the Taxonomic Data Center (TDC) where you will find lists of all plants in the United States, range maps, customized plant lists for any area you are interested in, etc.


1) When the TDC (Taxonomic Data Center) page opens, you will see three columns: Families, Genera, Species. You do not need to type in the family. In the yellow box “Search for Genus” (below the word “GENERA”) type in the genus name. When that genus name appears below the yellow box, click it. Now look in the next column to the right, the SPECIES column, and you will see a list of all of the species in the genus you just typed in.
Look farther to the right and you will see 4 maps. The upper left one will show every county in the U.S. which has the genus you typed in. Go back to the SPECIES column, click on any species, and the map will change to show all the counties for that species.
Below the 4 maps is a small box, “Hide photographs”. Click in the box and then click, “Show photographs”.
2) The plant names listed are the most up-to-date names. But what if you are using a scientific name that is not listed? How do you find what its current name is?  At the far left on the opening page of , above the “FAMILIES” column is a yellow box, “Infraspecific taxa”. Click it and then click “Checklist Format”. (Come back to the box later and click “Thesaurus Format”.) Clicking either of these options gives you synonyms. Let’s say, for instance, that you have been using Weber’s “Sabina” instead of “Juniperus”. Select “Thesaurus Format”, type in “Sabina” in the Genus column, click Sabina, and now you have a list in the Species column of 4 taxa that Weber calls “Sabina” but which BONAP indicates should be called “Juniperus”. The synonym, “Sabina” is in gray type; the accepted name, “Juniperus”, is in black type.

**Flora of North America. Click to read about.

SEINet  and  Intermountain Region Herbarium Network and their associated herbaria consortiums. Photographs and herbarium specimens from numerous herbaria. Superb. But remember that these websites (and similar collections for various regions around the U.S.) are compendiums, libraries. They show you in one location the holdings of dozens of herbaria in their region. They do not authenticate or vouch for their listings. They post the information that they have been given by dozens of herbaria. Unfortunately herbaria world-wide are understaffed and mistakes are common. All herbaria have mistakenly identified species.

Use all floral information from all sources with care. Always use multiple sources.
Colorado State's Herbarium  

USDA online Guide to U.S. Plants. Use with caution as it has been greatly neglected since about 2005. You will find much more accurate information on the Biota of North America Program website.

Edible and medicinal plant guides:
This Southwest Colorado Wildflowers website has only infrequent references to the edible and medicinal uses of plants.  Native people knew these uses, but over the past millennia, the sword, gun, and disease have exterminated almost all of these people and their knowledge.  The following texts provide an attempt by the conquerors to rediscover this lost knowledge.  Read all such books with care.  Compare what you are told in various books.  Please be sure to read the above material about not picking wild plants.

Edible and Medicinal Plants of Canada. Karst, Kershaw, & Ow. (Includes many plants of western U.S.)
Edible and Medicinal Plants of the Rockies
. Kershaw.
Edible Native Plants of the Rocky Mountains
. H. D. Harrington.
Nanise: A Navajo Herbal. Mayes and Lacy.
Western Medicinal Plants and Herbs. Foster and Hobbs. (Peterson Field Guide)
Wild Plants of the Pueblo Province. Dunmire and Tierney.


9) Native Plants Forums (Discussion Groups)

Do you have questions about native plants? Would you like to share information and enthusiasm about native plants? 

Join the Colorado and/or New Mexico Native Plants online botanical discussion groups for amateurs and professionals. Participate as much or as little as you want to. Send in photographs of native plants for identification and discuss key issues about conserving native plants, techniques for growing native plants in your garden, plant photography, etc. 

1)  Click to join the ColoradoNativePlant Facebook discussion group.

2)  Click to join the Colorado Native Plant Society Facebook Plant discussion group.

3Click to join the New Mexico native plant discussion group.