568 CLX. CYPERACE.E. FUIRENA. 



terior glumes ; stamens 3 ; style 3-cleft ; achenium triangular. ^ 

 Habit of Cyperus. 



1. M. OVULARIS. Vahl. (Cyperus. Gron. Torr. Scirpus echinatus. Linn.} 

 St. triquetrous, nearly naked, 1 2f high ; Ivs. shorter than the stem, 



nearly smooth ; umbel simple ; rays 3" 2' long ; hds. 1 5, globose, 1 sessile, 

 the rest on the spreading rays ; spikelets linear-subulate, 6" long, 50 100 in 

 each head ; fls. 2 4, 12 fertile ; invol. 3 4-leaved, outer leaves very long. 

 Bogs and low grounds, Middle and Western States, common. Aug., Sept. 



8. tenellus. Torr. Slender and csespitose ; hds. ovate, small. 



y. cylindricus. Torr. Hds. oblong, cylindrical. 



2. M. RETROFACTUS. Vahl. (Scirpus. Linn.} 



St. obtusely triangular, nearly leafless, pubescent, 2 3f high ; Ivs. pu- 

 bescent, 3 4" wide, about half as long as the stem ; umbels simple ; rays 

 unequal, long, 6 8; invol. 3 5-leaved; bracts unequal, not longer than the 

 rays; spikelets 70 100, subulate, 1-flowered, finally retrorsely imbricate into 

 obovate heads ; 2 lower glumes empty. A rare species, Middle and Western 

 States. Aug., Sept. 



4. KYLLINGIA. 



In honor of Peter Kylling, a Danish botanist. 



Spikelets compressed ; scales about 4, the two lowest short and 

 empty, the third only usually with a fertile flower; stam. 1 3; 

 style long, 2-cleft ; achenia lenticular. Stems triangular. Hds. ses- 

 sile, solitary or aggregated, involucrate. 



1. K. PUMILA. Michx. 



Caespitose ; st. 2 12' high, slender ; Ivs. mostly radical, shorter than the 

 stem, smooth ; hds. generally solitary, sometimes triple, closely sessile, oval or 

 oblong ; invol. 3-leaved, 1 2' long ; spikelets 1-flowered, very numerous, about 

 2" long; the lowest glume or glumes very small; sta. always 2; ach. lens- 

 shaped, fulvous. Wet banks, Columbus, Ohio (Sullivant!) Ky. (Short) and 

 Southern States. 



2. K. MONOCEPHALA. 



St. slender, 1015' high, leafy at base ; Ivs. much shorter than the stem, 

 1" wide; hd. simple, globose, dense, inclining; invol. 3-leaved, the highest 

 leaflet erect; spikelets numerous, 1-flowered; two lower glumes minute, two 

 upper striate, subequal, serrulate, ciliate on the keel. Mass., N. Y. to Ga. 



TRIBE 2. HYPOLYTRE^J. 



5. FUIRENA. Rottboll. 

 In honor of George Fuiren, a Dutch botanist. 



Glumes awned, imbricated on all sides into a spike ; petaloid 

 scales 3, cordate, awned, unguiculate, investing the achenium. % 



St. angular, leafy. Spikes subumbeled, axillary and terminal. 



1. F. SQJJARROSA. Michx. 



St. 1 2f high, obtusely triangular, sulcate ; Ivs. ciliate, shorter than the 

 stem ; sheaths hispid-pilose ; spikes clustered, ovate, mostly terminal, 6 12 ; 

 awns nearly as long as the glumes ; petaloid scales ovate, cuspidate with a short 

 bristle ; ach. twice the length of the stipe. Bogs and swamps, N. J. to Car. 

 Sept. 



2. F. PUMILA. Spr. (F. squarrosa. /?. Torr.) 



St. pubescent above, 3 6' high; Ivs. linear-lanceolate, flat, striate, as 

 long as the stem ; spikes 1, 2 or 3, thick, subtended by 2 3 long, involucrate, 

 unequal leaves ; glumes ovate-lanceolate, with short awns ; petaloid scales ovate- 

 lanceolate ; ach. pedicellate, with retrorsely hispid setae. Wet, sandy places. Ang. 



