Cactus are indigenous to the Western Hemisphere and are found in their greatest concentration along the Tropics of Cancer and Capricorn.  They are found in deserts, on seashores, in mountains, and on plains, balds, and glades.  Cactus are native to every American state except Vermont and Maine and they are as evocative of the western United States as Sagebrush. 

     Cactus come in a number of shapes from flat to cylindrical to circular; they are minute and gigantic; their flowers are commonly very large and attractive; their fruits are edible (some delicious, some not so); and they have evolved a number of structures and processes that make them perfectly at home in what we humans call "a hostile environment": They have a tough, waxy outer layer that reduces moisture loss; they produce chlorophyll not in leaves but in the outer cells of the stems; they convert absorbed water into a mucilaginous liquid that can be stored in large quantities in tissues capable of expanding; and many Cactus root easily into new plants from the broken pads or stems of older plants.

    "Cactus" is Greek for "prickly plant"; the word was used by Linnaeus in the 18th century to describe a prickly, thistle-like Asteraceae found in Italy.  "Cactus" was then used in the 19th century for the newly discovered spiny, drought resistant plants discovered in the Western Hemisphere.

There are a number of varieties of Opuntia phaeacantha, and all commonly grow three to five feet tall and wide, but in the Four Corners area they are most commonly ground hugging and sprawling.  Opuntia phaeacantha has pads that range from three to ten inches in diameter, one-to-three inch brown-tipped spines that are widely spaced, and, most often, yellow flower petals with red-to-orange tinting at the base. It is not unusual, though, to find pink and salmon flowers.

It is common to find Opuntia phaeacantha pads that have semi-circular chunks missing from them -- the work of deer. The smaller nibbles are taken by squirrels, chipmunks, and mice; the missing fruit has often been eaten by critters or has disappeared into collecting bags of humans who relish it for jams, pies, and muffins. 

"Phaeacantha" is Greek for "dusky thorn" referring to the brown-tipped spines.

Opuntia polyacantha plants are low and sprawling with pads two to six inches wide and long.  Spines grow close together with many arising from the same point. ("Polyacantha" is Greek for "many thorns".)  Flowers, ranging from yellow to hot pink (see below), are very large in relation to the pad size. New pads are soft, as are their short, undeveloped spines.  The winter of 2006-2007 produced ideal growing conditions for many plants, including these Cacti and you can see how much larger the new growth is.  Pads of some varieties and hybrids are elongated, as pictured here, but most are nearly circular.  The ideal 2006-2007 conditions favored bud and flower growth as well as pad growth.  There are nine buds ready to open. 

Opuntia polyacantha hybridizes readily and the Flora of North America now lists a number of varieties.  An entire former Opuntia  species,  O. erinacea is now broken into a number of varieties of O. polyacantha.  

Click for more O. polyacantha.

Semi-desert, foothills. Openings. Spring, summer.
Hidden Valley Trail, Utah, May 10, 2007 and Canyons of the Ancients National Monument, May 17, 2009.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Opuntia phaeacantha

Range map for Opuntia polyacantha