CYPERACE.E. (SEDGE FAMILY.) 573 



2. KYLLINGA, Ilottboell. (PI. 1.) 



Spikelets of 3 or 4 two-ranked scales, 1 -1-J-flowered; the 2 lower scales 

 miiiute and empty, as in Cyperus, 4, but style oftener 2-cleft and achene 

 lenticular ; spikes densely aggregated in solitary or triple sessile heads. 

 Culms leafy at base ; involucre 3-leaved. (Named after Peter Kylling, a Dan- 

 ish botanist of the 17th century.) 



1. K. pumila, Michx. Annual; culms 2-9' high; head globular or 

 3-lobed, whitish-green (about 4" broad); spikelets strictly 1-flowered; upper 

 scales ovate, pointed, rough on the keel ; stamens and styles 2 ; leaves linear 



- Low grounds, Ohio to 111., south to Fla. and Tex. Aug. 



3. DULICHIUM, Pers. (PL 1.) 



Spikelets many- (6- 10-) flowered, linear, flattened, sessile in 2 ranks on ax- 

 illary solitary peduncles emerging from the sheaths of the leaves ; scales 2- 

 rauked, lanceolate, decurrent, forming flat wing-like margins on the joint below. 

 Perianth of 6 - 9 downwardly barbed bristles. Stamens 3. Style 2-cleft above. 

 Achene flattened, linear-oblong, beaked with the long persistent style. A 

 perennial herb, with a terete simple hollow culm (1-2 high), jointed and 

 leafy to the summit; leaves short and flat, linear, 3-ranked. (An alteration 

 of Dulcichinum, an old name for a species of Cyperus.) 



1 . D. spathaceum, Pers. Borders of ponds, N. Scotia to Fla., west to 

 Minn, and Tex. July - Sept. 



4. ELEOCHARIS, R. Br. SPIKE-RUSH. (PI. 3.) 



Spikelet single, terminating the naked culm, many -several-flowered. Scales 

 imbricated all round in many (rarely in 2 or 3) ranks. Perianth of 3 - 12 (com- 

 monlv 6) bristles, usually rough or barbed downward, rarely obsolete. Sta- 

 mens 2-3. Stvle 2-3-cleft, its bulbous base persistent as a tubercle jointed 

 upon the apex of the lenticular or triangular achene. Leafless, chiefly per- 

 ennial, with tufted culms sheathed at the base, from matted or creeping root- 

 stocks; flowering in summer. (Name from e'Aos, a marsh, and \aipw, to delight 

 in ; being marsh plants. ) 



1. Spikelet terete, hardly if at all thicker than the spongy-cellular culm ; scales 

 flrmly persistent; style mostly 3-c/eft ; bristles 6 (rarely l),firm or rigid, 

 mostly barbed downward, equalling or surpassing the triangular or lenticular 

 achene. 



* Spikelet linear or lanceolate-awl-shaped, few-flowered ; scales (only 3 -9) few- 



ranked, convolute-clasping the long flattened joints of the axis, lanceolate, 

 herbaceous (green) and several-nerved on the back, and with thin scarious 

 margins. 



1. E. Robbinsii, Oakes. Flower-bearing culms exactly triangular, rather 

 stout, erect (8' -2 high), also producing tufts of capillary abortive stems or 

 fine leaves, which float in the water; sheath obliquely truncate; spikelet 4- 

 10" long; achene oblong-obovate, triangular, minutely reticulated, about half 

 the length of the bristles, tipped with a flattened awl-shaped tubercle. Shal- 

 low water, N. Eng. to Fla. 



