Monographs Details: Hassalia heterogenea
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 very short, much contorted, with smooth, gentle curves, moderately branched, about equally single and geminate branching, soon recurving, 13-16 µ diam.; trichomes 9.5-13 µ diam., not constricted at the dissepiments, or only moderately so in part; cells quadrate in the older parts, one-half to one-fourth as long as the diameter at the apices, pale aeruginous, homogeneous; heterocysts of the same shape and size as the contiguous cells; not abundant; sheath close-fitting, thin, homogeneous, dark brown.
Distribution and Ecology - Growing on rocks at Hacienda Holm, Mayagiiez, no. 1191, type; on lava rock at Coamo Springs, nos. 1923 a and 1921.
PLATE 19, FIGURE 42
The above-described species might be almost equally well placed in either Scytonema or Hassalia. On account of its diminutive size and short branches I have placed it in the latter genus.