Rocky Mountain Alpineparsley

Oreoxis humilis Raf. Bull. Bot. Seringe, 1: 217. 1830
Cymoplerus humilis Tidestrom in Tidestrom & Kittell, Fl. Ariz. N. Mex. 325. 1941.
Plants 2-15 cm. high, the base of the umbel and the inflorescence occasionally puberulent; leaves oblong in general outline, excluding the petioles 5-45 mm. long, 5-10 mm. broad, 1-2pinnate, the ultimate divisions mostly distinct, 2-10 mm. long, 1-2 mm. broad; petioles 1-4.5 cm. long; peduncles 1-13 cm. long; involucre rarely of an inconspicuous linear bract; involucel dimidiate, the bractlets linear, 3-5 mm. long; rays 3-9, 2-5 mm. long; flowers yellow; fruit oblong, somewhat boat-shaped, 3-5 mm. long, 1.5-3 mm. broad, glabrous, the wings broadly linear, usually rounded at the apex in cross section, the lateral broader than the dorsal; oil-tubes 1-3, usually 3, in the intervals, 3-6 on the commissure.
Type locality: Rocky Mountains. Colorado, James.
Distribution: Alpine, region of Pikes Peak, Colorado {Clements &* Clements 435, Letlerman 177).

Cymopterus humilis, synonym Oreoxis humilis, is a rare species of flowering plant in the carrot family known by the common name Rocky Mountain alpineparsley. It is endemic to Colorado in the United States, where it is known only from the vicinity of Pikes Peak. There are three occurrences, for a total population of about 4240 individuals.

This perennial herb grows about 12 centimeters tall and blooms in yellow flowers during the summer. It grows on granite substrates above the tree line.

The plant is threatened by construction and maintenance on the Pikes Peak Highway.