Family: Caryophyllaceae Juss.
Distribution: Central part of North America, found in Rocky Mountains, reaching western edge of prairies, from southern Alberta to north of Arizona and Texas.
Ecology: On dry rocks, rocky slopes, sandstone in elevations from 700 to 3100 m. Blooms in summer.
Description: Perennial herb, forming cushions, up to 30 cm across, woody caudex. Stems decumbent to erect, branched, 5–25 cm long. Leaves linear, 4–7.5 × 0.5–0.8 mm, opposite, overlapping, spine-tipped. Flowers solitary or in pairs, teminal, pale yellow, less than 6 mm across; sepals 5, 1,5–2 mm, yellow, bristly, lanceolate; petals absent. Fruit is a utricle, 1.5 mm long, inflated, single-seeded.
These images were taken in Canada, Alberta, Calgary, Confluence Park (August 5, 2013).
