North American Cyperacea. 326 
the western parts of the State of New York, Dr. Gray ! ; on 
the Missouri above St. Louis, Dr. Baldwin! 
y. cylindricus. Spikes cylindrical-oblong, somewhat acute ; 
scales ovate, somewhat pubescent, aristately mucronate ; bristles 
about 4, rigid, nearly as long as the nut; style 3-cleft; nut 
obovate, abruptly acuminate, narrowed below, obtusely angular 
in front, flat on the back, smooth. 
Culm and innhel as in the preceding variety. Spikes an inch long, 
and only one-third of an inch in diameter. 
Hab. Georgiz, Dr. Baldwin! 
Obs. The variety (2. differs so much from the common S. 
maritimus of our salt marshes in the appearance of the ripe spike 
and in the form of the nut, as well as in the length of the bristles, 
that I should have proposed it as a distinct species, did not the 
succeeding variety connect the two, and seem to show that they 
are all forms of one species. Which of the three is the S, 
maritimiis of Europe I am unable to say, as my foreign speci- 
mens are not sufficiently mature to exhibit the ripe fruit. The 
first variety seems by its lenticular smooth nut, to be exactly 
S. maritimus of N. ab Esenb. (1. c.) ; but Roemer and Schultes, 
in their detailed description of the same species, state that 
the nut is triquetrous, and the bristles equalling it in length. 
Smith, (in Eng.fl. 1. p. 61) describes the nut as " roundish, 
shining brown, with 3 blunt angles, and from one to five or six 
rough bristles." Perhaps both varieties occur in Europe, as 
they do in this country ; the one being confined to the neigh- 
bourhood of salt water, and the other inhabiting the borders of 
fresh water rivers and lakes. 
9. SciRPUS ATROVIRENS, MuhL 
Culm triangular, leafy; umbel compound, proliferous; invo- 
lucre about 3-leaved ; spikes ovate, acute, glomerated in dense 
heads of 15 — 20; scales ovate, mucronate, pubescent; bristless 
as long as the nut ; style 3-cleft ; nut obovate, minute, com- 
pressed-triangular, tapering towards the base, acuminate, dull. 
