Monographs Details: Tolypothrix amoena N.L.Gardner
Authority: Gardner, Nathaniel L. 1927. New Myxophyceae from Porto Rico. Mem. New York Bot. Gard. 7: 1-144. pl. 1-23.
Family:Microchaetaceae
Description:Species Description - Filaments 10-15 µ long, 22-26 µ diam., densely interwoven into a pannose stratum, very smooth and of equal diameter throughout the entire length; trichomes cylindrical, constricted in part at the dissepiments, 16-18 µ diam., of the same diameter throughout the entire length; cells in part short cylindrical and in part dolioform, one-third to one-fifth the diameter long, homogeneous or very finely granular, bright aeruginous, changing to yellowish or greenish gray on drying; sheath very smooth and straight, homogeneous, hyaline to slightly brownish; heterocysts ranging from almost cylindrical and longer than the diameter through quadrate, spherical, to very much compressed, becoming disk-shaped, prevailingly spherical, single or 2-5-seriate, very numerous throughout the trichome; branching sparse.

Distribution and Ecology - Growing in a pool west of the Experiment Station, Rio Piedras, no. 1932, type, and nos. 1935, 1936, 1941, 1943, 1945, and 1952; in a stream about five kilometers east of Coamo, no. 221 c.

Discussion:

PLATE 20, FIGURE 48

Tolypothrix amoena is a very distinct species, being very definite in all of its characters. It has long, relatively straight and rigid filaments. The sheath is firm, smooth, and homogeneous. In some parts of the trichome the heterocysts are almost cylindrical, in others they are spherical and in still others very much compressed, but always very distinct and conspicuous. The cells are either perfect, short cylinders with no constrictions, or dolioform and conspicuously constricted.