Gloeocapsa acervata

• Region

  West Indies

• Country

  Puerto Rico

• Locality

  Arecibo to Hatillo, on limestone

• Coordinates

  18.4214, -66.7315

• Distribution

  Map all specimens of this taxon

NEW YORK BOTANICAL GARDEN

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DARIUS OGDEN MILLS FUND

FRESH-WATER ALGAE OF PORTO RICO
COLLECTED BY PROFESSOR N. WILLE
Arecibo to Hatillo February 27, 1915

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COELECTED BY PROFESSOR N. WILLE
Arecibo to Hatillo February 27, 1905

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Gloeocapsa acervata sp. nov.

Plate 2, figure 22

Families very variable as to the number of cells they contain
as well as to their shape and size, having up to 256, probably
even more cells, spherical to slightly elongated and lobular, piled
together in heaps, adhering by their very soft, gelatinous walls
and forming a continuous stratum; cells spherical, 0.9-1.3 n
diam., bright aeruginous, regularly arranged in the young fam-
ilies, or colonies, soon arranging themselves-in no definite order
in the older families; tegument hyaline or almost transparent in
the younger colonies, changing to honey-color, or later to dark
brown, homogeneous throughout the colony.

Growing on limestone between Hatillo and Arecibo, no. 1390,
type, and no. 1393 ; near Hato Arriba, Arecibo, no. 1425.

It is questionable as to whether the above newly described
organism should be considered as belonging to the genus Gloeo-
capsa or to the genus Anacystis. It is a borderline species. In
its very youngest stages, it conforms to the Gloeocapsa method
of development. The colonies of two, four, and eight are more
or less angular, the cells are symmetrically arranged, and in
some cases a slight stratification of the tegument may be seen. *

The colonies soon become spherical, the cells are promiscuously
arranged, and with no indication of stratification of the tegu-
ment. They then resemble typical members of the genus Ana-
cystis. Their teguments are sticky, and the growing colonies
become agglutinated into masses with lobular surfaces, in this
stage superficially resembling Microcystis ichthyoblabe Kuetz.
There seems to be no especially visible modification of the cells
to form resting spores at the end of the life cycle. The tegu-
ments finally seem to become completely confluent, and the cells,
probably after a period of rest, begin actively to divide and new
colonies are formed in position. This seems to bo a typical