Monographs Details: Hassalia discoidea
Authority: Gardner, Nathaniel L. 1927. New Myxophyceae from Porto Rico. Mem. New York Bot. Gard. 7: 1-144. pl. 1-23.
Description:Species Description - Filaments scattered among other algae, not forming a definite stratum alone, relatively short, comparatively straight, 22-25 µ diam. in main filaments, less in the branches; branching moderately frequent, simple under the heterocysts and appressed; trichomes much constricted at the dissepiments, 17-20 µ diam., uniform throughout the entire length; cells discoid, 4-6 µ long, or slightly longer in the oldest parts, bright blue-green or methyl green, finely granular; heterocysts of the same shape and size as the cells, golden yellow, numerous; sheath 2-3 µ thick, smooth, homogeneous, hyaline, changing to yellowish.
Distribution and Ecology - Growing on rocks in association with Hepaticae and with other species of Myxophyceae, about seven kilometers east of Coamo, no. 1870, type.
PLATE 19, FIGURE 43
This species is closely related to H. scytonematoides of this paper. The cells are more discoid and of a brighter green color, and the sheath is thin, firm, not lamellose nor ocreate.