North American Cyperacea. 281 
exterior ones, free their whole length in the mature spikelet, and resem- 
bling a 2-valved perianth. Statnens 3 (2 in the superior florets). Style 
3-cleft one third of its length; the segments revolute. Nut ovate, acute, 
half as long as the scale, compressed-triangular, flattened on the back, 
smooth and shining. 
Hab. Wet places, particularly on the banks of rivers. 
Pennsylvania, North Carolina and Georgia, Miihhnherg! ; 
Delaware, Dr. Baldic'm ! ; Middle Florida, Dr. Chapman! ; 
New Orleans, Dr. Ing-alls ! 
The following species of C^nperus, recorded by Pursh and other writers 
on North American Botany, are omitted, as they either do not belong to 
our Flora, or cannot be identified by the imperfect descriptions of the 
authors who have noticed them. 
1. C. AtJTUM>"ALis, Pursh, fl. 1. p. 51. (excl. syn.) 
Along the margins of ponds and ditches. Virginia and Carolina. 
— Pursh. 
This species was founded by Vahl on the Scirpus autumnalis, Rotth. 
and Linn., which is a species of Trichclostylis {Scirptis L.) The Cyperus 
complanatus, Wdld. and Scirp. foliis pusillus autumnalis, &c. Clayt. 
772, which Vahl refers to his C- autumnalis, likewise belong to Sr-spe- 
c'ie^ja£ Trichelostylis (T. complanata, N. ah E.) The C. juncoides of 
Lamk., another of Vahl's synonyms, is an E ast Indian species. Pursh's 
plant seems to be C. articulatus. 
2. C. TENuiFLORUS, PuTsh, fl. 1. p. 52. (not of Botth., Vahl, Elliott, 
and Others.) 
In wet fields in Carolina and Georgia, Pursh. 
Pursh has probably confounded some other species with the C. tenui- 
florus of RottbcEll. 
3. C.FiiiciJTUS. Spikeletslinear-lanceolate, somewhatremote, loosely 
imbricated ; involucre 3-leaved, longer than the umbel, and, as also the 
leaves, lax. Culm half a foot high, filiform, acutely angular, as long as 
the leaves, lax. Leaflets of the involucre resembling the leaves; involu- 
cels wanting. Ochrea truncate. Umbel somewhat compound, 3 — 4- 
rayed ; rays an inch or more in length ; partial umbels 3-rayed ; the rays 
very short. Spikelets 4 — 8, scarcely half an inch long, 12-flo-wered, 
