Weber's Colorado Flora places some species of Chickweeds in Alsinaceae, not Caryophyllaceae.

Foothills, montane, subalpine, alpine. Open woodlands. Summer, fall.
Above: Taylor Mesa, June 30, 2020.
Left: Horse Creek Trail, August 31, 2005; Taylor Mesa, July 6, 2010; Cross Mountain Trail, July 22, 2016.

Arenaria lanuginosa is typically found sprawling along the ground making very loose, open mounds with 3-7 inch stems topped by bright white flowers.  Stems can be much longer (to 18 inches) and the stems can be upright.

Rounded white petals are slightly longer than the pointed green sepals.  Just after the flowers open the ten stamens are arched back over the petals. As the flower matures the stamens grow erect, pollen matures, and eventually the anther sacs fall. The sacs are pink, to white, to brown depending on their age. In the photograph below you can see that 5 of the 10 stamens still have their anther sacs. In the very center of the flower are the three spreading styles.

In the Four Corners region this fairly common Chickweed most often occurs scattered along trails through open Spruce forests.  The bright white flowers will attract your attention.

Although most Arenaria lanuginosa in the Four Corners area are fairly uniform in their morphology, the Flora of North America indicates that this species "is morphologically diverse... and is in serous need of comprehensive study."

The Spergulastrum genus was named by Michaux in 1803 and Michaux also named this species.  "Lanuginosum", from the Latin for "wool" and "full of", perhaps refers to the densely hairy leaves and stems.

Linnaeus named the Arenaria genus in 1753 and Paul Rohrbach (1846-1871) posthumously renamed Michaux's Spergulastrum lanuginosum to Arenaria lanuginosa in 1872.  The Flora of North America, the Synthesis of the North American Flora, and A Utah Flora place this species in the Arenaria genus. 

"Aren" is Latin for "sand" and is aptly applied because of the often sandy areas that species of this genus grow in.

Click to read about Chickweeds..

Foothills to alpine. Meadows, moist areas. Summer, fall.
Above top, below left, and below right: Ryman Creek Trail, July 8, 2019.
Second photograph above: Lizard Head Pass Meadow, July 15, 2020.
Immediately above: Near Grindstone Lake, July 10, 2020.
Left: Horse Creek Trail, August 31, 2005.

Stellaria longipes grows to a very slender two-to-eight inches tall. Typically it is just 3 or 4 inches tall.  It enjoys open meadows, dry forests, and wet areas and thrives from the foothills to the alpine.  Its stem leaves are narrow, sometimes slightly cupped, and lustrous green, generally angling upward. In the top photograph above, the white dots are Stellaria longipes and you can see how inconspicuous this species is, but when it is looked at closely, as in the three photographs above, it is a delicate work of art. 

Five white flower petals are deeply cut and much longer than the sepals (green with a mid-vein, behind the white petals).

As is true of Arenaria lanuginosa shown above, it is the bright white flower, not the greenery of the plant that will first attract your attention. The plants are so inconspicuous that without the flower they would be unnoticed, unless you find a patch of them as shown above. Such large patches of them are not unusual as the plant is rhizomatous.

The genus name, Stellaria, is Latin for "star" and was given by Linnaeus in 1753.  "Longipes", a name given by John Goldie (1793-1886), is Latin for "long limbed", referring to the plants very slender stature.  Click to see the very similar Stellaria longifolia.

Foothills to alpine. Meadows, moist areas. Summer, fall.
Lizard Head Meadow, June 26, 2020.

The plant at left puzzled me so I submitted it to several authorities. They all agreed it is S. longipes, but it is one that shows some unusual leaf characteristics. The plant at left grows within a few feet of the three S. longipes shown side by side above. My wife and I scoured the area within three hundred feet of the plant at left. We found dozens of Stellaria longipes that were all clearly the standard-looking S. longipes. We collected several of these for the University of Colorado herbarium.

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 Arenaria lanuginosa

Range map for Stellaria longipes