Mcdonnell, A. and Fishbein, M. 2016.

Polystemma canisferum (Apocynaceae, Asclepiadoideae): a distinctive new gonoloboid milkweed vine from Sonora, Mexico

. Phytotaxa. 246, 1 (Feb. 2016), 78–84. DOI:https://doi.org/10.11646/phytotaxa.246.1.6.