205 
A Preliminary List of North American Species of Cyperus, wit if 
Descriptions of new Forms. 
By N. L. BRITTON. 
(A) Sub-genus PycrEus, Beauv. 
* Umbel simple or capitate, rarely slightly compound. 
t Superficial cells of the achenium oblong. f 
1. Cyperus flavescens,L. Canada to Texas throughout east- 
ern North America ; also in northern Mexico, Brazil, southern 
Europe, northern Africa and western Asia. : 
t t Superficial cells of the achenium quadrate. : 
2. C. diandrus, Torrey. Throughout eastern North 
America, extending westward to Arkansas and New Mexico. 
(Fendler, No. 869.) 
Var. castaneus, Torrey. (C. Elliottianus, Roem. and Schultes, 
Mant. ii, p. 100.) With the type. I cannot agree with Mr. C. 
B. Clarke, (Journ. Linn. Soc., xxi., p. 65) in regarding this plant 
as a distinct species under the name C. rivudaris, Kunth. The 
varieties e/uta and depauperata which he proposes (I. c.) are, in 
my opinion, but forms of the variable C. diandrus. There is 
still another form, characterized by elongated spikelets, which 
has been collected by Hunter in Lincoln Co., N. C., and by Leg- 
gett at Summit, N. J. 
Var. CAPITATUS, n. var. Inflorescence a single capitate cluster 
appearing somewhat lateral; involucre of one or.two elongated 
leaves with one or two bracts; glumes generally brown-mar- 
gined. Texas and northern Mexico to California. Here I in- 
clude the var. castaneus of Watson in Botany of California, ii., p. 
214; No. 1949 of C. Wright’s New Mexican Collection, and No. 
49a of Dr. Palmer’s Chihuahuan Collection of 1885. 
3.. C. bipartitus, Torrey. New Orleans, La., (Dr. Ingalls 
in Torrey Herbarium.) This appears to be distinct, but more 
specimens are needed to establish its relationship; it may be but 
a single-spiked form or variety of C. diandrus. 
4. C. Nutiallii, Eddy in Spreng. Neue Entdeck., i., p. 
240; Torrey. In salt meadows along the Atlantic and Gulf 
coasts (Curtiss, N. A. Plants, 3050.) For synonomy see Torrey, 
Ann. Lyc., iii, p. 252. C. Cleaveri, Torrey, is but a crueenes; 
ate, eecig spiked form, of this species. ‘ 
