Monographs Details: Nostoc brittonii 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 spherical, up to 2 mm. diam., firm, smooth; trichomes very tortuous, moderately crowded, 3.6-4.8 µ diam.; cells dolioform to subspherical, bright violet or drab, fading to greenish; heterocysts spherical, single in the juvenile stage of the trichome, later, on the formation of hormogonia, two or more are formed, these usually being somewhat smaller; tegument opalescent when young, changing to purplish drab, and finally to yellowish brown; resting spores unknown.

Distribution and Ecology - At "Campo" south of Maricao, collected by Dr. N. L. Britton, no. 1290 a, type; collected by Dr. Wille in the same locality, no. 1229 c.

Discussion:No resting spores have been observed in the material of this species of Nostoc. Some of the colonies, however, are mature and have formed hormogonia with definite individual teguments showing the beginning of new colonies. After having been dried, the color seems to diffuse out of the trichomes into the tegument when wet.