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.
Family:Microcystaceae
Scientific Name:Hassalia discoidea
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.

Discussion:

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.