Monographs Details: Hypheothrix willei 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:Oscillatoriaceae
Description:Species Description - Filaments prostrate, distributed among other algae, about one-half mm. long, 40-60 µ diam., more or less irregularly branched, fairly definite and smooth on the surface; trichomes 1-3 in a sheath, 5.2-5.4 µ diam., straight, not constricted, long and sharply attenuated at the apices; cells quadrate to slightly greater or less than the diameter, pale aeruginous, densely congested with relatively large granules evenly distributed; crosswalls very thin; 4-6 apical cells forming an acute cone; sheath hyaline in the juvenile stage, changing with age in part to light pink or salmon, homogeneous.

Distribution and Ecology - Growing among other Myxophyceae on rocks west of Humacao, no. 613 b, type.

Discussion:

PLATE 10, FIGURE 98

In placing this species I have weighed the slight coloration of the sheaths against other characters and decided to place it with Hypheothrix, although that genus has been limited to include only those forms with hyaline sheaths.