Monographs Details: Anacystis nigropurpurea 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:Microcystaceae
Description:Species Description - Colonies subspherical, free, 25-40 µ (up to 70 µ) diam.; cells spherical to slightly ellipsoidal, 3.5-4.5 µ diam., with a distinct dark purplish wall, contents homogeneous, obscured by the more or less opaque wall, moderately close together, arranged without order in the colony; resting cells 5-6 µ diam., with dark, smooth, homogeneous wall; tegument hyaline or opalescent, homogeneous, close-fitting or with a distinct clear margin between the cells and the surface.

Distribution and Ecology - Growing in depressions in limestone between Hatillo and Arecibo, no. 1387 a, type; on limestone, Hato Arriba, Arecibo, nos. 1397 a and 1399 c; on a waterpipe in company with other Myxophyceae, Maricao, no. 1155 f; on the wall of a church, Sabana Grande, no. 962 o; on bark along the road to Monte Montoro, Maricao, no. 1087.

Discussion:

This species of Anacystis is one of a few species in which the cells develop a distinct, colored wall very early in the life cycle. The distinction between the vegetative cells and the resting spores is slight. The latter are somewhat larger and the cell walls are thicker, but of the same color and consistency.

Anacystis nigropurpurea seems closely related to A. nigroviolacea of this paper. The former has more and smaller cells in a colony than the latter. The especially distinguishing feature separating the two species is in the method of development. In germination, the resting spore of .1. nigropurpurea apparently retains the spore wall, which, however, becomes thinner, the subgelatinous tegument being secreted on the outside of the wall, and is colorless from the beginning of germination to maturity.

On the contrary, the resting spores of A. nigroviolacea on germination secrete the gelatinous matrix, or tegument, on the inside of the wall, which moves outward from the protoplast, becomes thinner and apparently modified, and loses much of its color. The new tegument remains faintly colored throughout the life cycle. The modification of the spore wall does not seem quite so profound as in the case of A. gigas, A. magnified, etc., of this paper, in which the original morphological character of the wall is entirely lost.