Plant: perennial herb, vegetative parts typically roughened with a fine pubescence; stems ascending to rather decumbent, unbranched, 10-80 cm tall; milky sap Leaves: irregularly alternate, the petioles 2-11 mm long, the blades lanceolate to less often linear-lanceolate, 5-19 cm long, 6-27 mm broad, acute or infrequently obtuse at the base, long attenuate to an acute apex INFLORESCENCE: UMBELS solitary and terminal, 4-7 cm broad, sessile or more often long-pedunculate with the peduncles to 20(-30) cm long Flowers: large; calyx lobes 3-6 mm long; corolla greenish, uncommonly purple-tipped, bowl-shaped, the lobes curved-ascending, 9-12 mm long; hoods sessile and attached along the entire height of the column, oblong-tubular, "J"- to "C"-shaped, spreading-descending at the base and gradually curving upward near the middle, the upper portion erect to incurved, ca. 5-8 mm long, 2-2.6 mm broad at the median bulge, about as high as the gynostegium, the horns radially flat, attached in the top of the hoods, triangular, entirely included within the hood margins; anther wings 1.8-2 mm long; corpusculum 0.3-0.4 mm long, the pollinia 1.2-1.4 mm long Fruit: follicles erect on deflexed pedicels, 5-10 cm long REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 169-187.
There is little information specifically about the use of Asclepias asperula on the web (2016-09-05), most sources stating that it probably has the same uses and properties as other species of Asclepias. One exception is a video by Ginger Webb who states that the drops from a tincture made of ground up roots is used in midwifery and to relieve congestion and heart problems. She, like others who write about using Asclepias species, emphasizes that the plants are very toxic and discourage their medicinal use by lay people.