Monographs Details: Nostoc simulans N.L.Gardner
Authority: Gardner, Nathaniel L. 1927. New Myxophyceae from Porto Rico. Mem. New York Bot. Gard. 7: 1-144. pl. 1-23.
Description:Species Description - Thallus of no definite shape, more or less confluent, soft and gelatinous; trichomes moderately tortuous, constricted at the dissepiments, 2.4-2.6 µ diam., 1.5-2 times as long as the diameter; heterocysts spherical, about 3 µ diam., resting spores cylindrical to ellipsoidal, 3.8-4.2 µ diam., 6.8-7.5 µ long, walls smooth, hyaline.

Distribution and Ecology - Growing in cavities in the wall of a house in Maricao, no. 1117, type.

Discussion:The species proposed here belongs to the section Humifusa of Bornet and Flahault, as a close relative in all appearances tc N. humifusum Carmichael.