Monographs Details: Scytonema tenue 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 - Filaments mostly straight, erect, parallel, closely associated, forming a velvety stratum, sparsely branched, the branches arising near the base, 0.75-1 mm. high, 6-8 µ diam.; trichomes 5.5-6.5 µ diam. at the apices, 2-2.5 times as long in older parts; cells cylindrical in the body of the filament, and not constricted, slightly dolioform at the apices, pale aeruginous, homogeneous; sheath subgelatinous, hyaline, homogeneous, 2-2.5 µ thick; heterocysts cylindrical, quadrate to 2 times as long.
Distribution and Ecology - Growing on rocks at a water reservoir, Rio Piedras, no. 106, type.
PLATE 17, FIGURE 36
The closest affinities of this species of Scytonema apparently are S. tenuissimum Schmidle, a smaller species with thinner sheath, and 8. intermedium De Wild., a larger species.