Monographs Details: Anabaena unispora 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:Nostocaceae
Description:Species Description - Stratum thin, slightly mucous, or trichomes intermixed with other algae; trichomes short, for the most part straight, slightly attenuated for several cells; cells cylindrical, slightly constricted at the dissepiments, 4r4.5 n diam., 1.5-2 times as long as the diameter, containing few to many small granules; terminal cells blunt, heterocysts slightly larger in both dimensions than the cells, one, or rarely two, in a trichome; spores single, developing at one side of the heterocyst, narrowly to broadly ellipsoidal, variable'in size, 20-34 n long, 13-20 p broad, with a smooth thin hyaline membrane, or at times the inner layer slightly brownish in color.

Distribution and Ecology - Growing in a pool among other algae and debris near the Park, Santurce, no. 49 a, type, no. 44 c, and no. 51 d.

Discussion:

PLATE 12, FIGURE 8

The very conspicuous character of this species of Anabaena is the production of a single resting spore by each plant. The large majority of plants produce but a single heterocyst, although there are occasionally two in a plant. In case there are two usually one is located near the end of the trichome and the other near the center in its characteristic position. However, no plants were seen with more than one spore. In number 47 c of the collection, and in scattered filaments in several other collections, the plants are young and the spores are sparse, but in number 51 d the material is thoroughly mature and the spores are numerous. It is difficult to ascertain its nearest relatives.