Sarcostemma crispum

Similar to narrow-leaved forms of Sarcostemma cynanchoides, this species is both uncommon in southern New Mexico and, in my experience at least, rarely in flower. I have seen the vegetative stems a half-dozen times but as of yet no flowers. The leaf texture differs substantially in gestalt from that of S. cynanchoides, but since leaf shapes overlap entirely and even the crispate margins that give rise to S. crispum's specific epithet can be found occasionally in S. cynanchoides, the length of fruiting peduncles is the best character to distinguish the two species. This character is, however, worded somewhat misleadingly in many keys. Peduncles of S. cynanchoides are from 3/4 as long as to slightly longer than the subtending leaves. Peduncles of S. crispum average ca. 1/3 as long as the subtending leaves.

Flowers on the west side of the Sacramento Mountains southwest of Bent, Otero County, New Mexico, 9 Aug 2009.

A flowering stem on the west side of the Sacramento Mountains southwest of Bent, 9 Aug 2009.

A vegetative stem, twining away on the east side of the Big Burro Mountains, Grant County, New Mexico, 22 Sep 2007.

A cauline leaf on the east side of the Big Burro Mountains, 22 Sep 2007.