362 North Avierican C^jperacea. 
about 3 lines long, ovate, terete, 16 — 20-flnwered. Scales ferruginous, 
of a pretty firm and somewhr< coriaceous texture, minutely and pulver- 
ulentlv pubescent, strongly 1-nerved so as to appear almost carinate. 
Stamens constantly 2. Styie (above the tubercle) filiform, equal, 2-cleft 
half-way down, separating early and completely from the tubercle. Nut 
orbicular, moderately convex on each side, marked with strong undulate 
transverse wrinkles, of alight brown colour, margined. Tubercle gray, 
much dilated, closely sessile, somewhat 2-lobed at the base ; the apex 
very blunt. 
Hab. Texas, T. Dnimmond ! 
Obs. This species resembles the preceding, but it differs 
in its much larger size, decompound cyme, many-flowered 
spikes, subcoriaceous scales, and in some other respects. It 
was distributed in the first collection of INIr. Drummond's 
Texian plants, under the No. 279. The last two species differ 
so much from F. scirpoides, that they might almost be referred 
to a separate genus. They are nearly related to Rhynchospora, 
but want the hypogynous bristles, and bear the same relation 
to that genus that Isolepis bears to Scirpus. In P. scirpoides 
the style is almost wholly persistent, compressed and subulate, 
without any distinct tubercle ; W'hile in P. rhynchosporoides and 
P. Texensis it is very caducous, with the exception of the base, 
which is enlarged into a tubercle of an entirely different texture 
from the nut. To the latter section belongs another species of 
which I have had two varieties in my herbarium ; one from 
St. Vincent, sent to me without a name by Dr. Lindley, the 
other received from Mr. Arnott, under the name of ScKcpmus 
Teneriffce, Vent. Mss. The culm is very slender, the branches 
of the cyme filiform and divaricate ; the spike 2 — 3-flowered, 
minute ; the nut lenticular, corrugated, and crowned with a 
short apiculate tubercle. 
The following revision of the North American species of 
Rhynchospora and Ceratoschoenus was prepared by Dr. Gray. 
His valuable Monograph contained in the present volume of 
