Pithophora mooreana Collins

Pithophora Mooreana nov.sp.lwwbeyt, Tufts Coll.stud.
Sci.Ser.3:97.Ap 1912.
Hayden,1910, p. 47;P.B.-A.,Ho.1637. Filamentis primariis
95-140 u diam.,ramis solitariis vel oppositis,75-100 p. diam.,
elongatis ,sensim attenuatis.plerumque in akinetam desinentibus;
cellulis plerumque longis, ad 20 diam. .interdum multo brevior-’
ibus.precipue inter duas akinetas; akinetis intercalaribus
diametrum filamentorum aequantibus vel paùllo minus, stricte
cylindricis. l-g-4 diam. longis ; akinetis terrninalibus ad plurimos
ramulos.conicis.circa 50 u diam.,ad basin subrotundatis, 125
longis.ad apicem rotundatis; akinetis et cellulis vegetativis'
plerumque regulariter alternantibus, rairralis longioribus brevior-
ibusve saepe ex alfinetis exeuntibus. interdum cum akinetis conti-
nuis; vel ex akineta ramulo.akinetis et cellulis vegetativis
alternatim positis, constante; akinetis ramuliferis ceteris ple-
rumque brevioribus.
Main filaments 95-140 ji diam..branched, branches solitary
or opposite, 75-100 p. diam.' long, gradually tapering, usually
ending in an akinete; cells usually long, up to 20 diam.,but
sometimes much shorter, especially when between two akinetes;
intercalary akinetes of about the same diameter as the fila-
ments or slightly smaller, strictly cylindrical, 1^-4 diam.
long; terminal akinetes on most of the branches, conical.about
50 ji diam. at the somewhat rounded base, 125 p. long to the
rounded tip. Akinetes and vegetative cells usually in regular
alternation, longer or shorter branches frequently proceeding
iron? akinetes, of ten continuous with the akinetes; or thè branch
from the akinete may consist of alternated akinetes and vegetat-
ive cells; branch-bearing akinetes usually shorter than the
others. Pig.9.In a pond in which Japanese plants were cultivated,
Missouri Botanical Garden, St. Louis, Mo.,C.T. Moore. Type in
herbarium, P.S.C.
The nearest relative seems to be p.sumatrana (Mart.)Wittr.,
from which it differs by the abundant terminal akinetes, and
especially by the branches proceeding from the akinetes.