154. CYPEKACEJS. 369 



$ 1. Spike solitary, one (rarely more; borne on each culm.. .(J) 

 II. Spikes two or more. Stigmas 2. Achenium lens-shaped.. .(.) 

 III. Spikes two or more. Stigmas 3. Achenium triangular... () 

 Stigmas 2. Achenium lens-shaped or flattened. . .(a) 

 Stigmas 3. Acheuium triquetrous or 3-angled.. .(6) 



a Spike androgynous, staminate at the summit No. 1 



a Spike dioecious, or the 8 spike staminate at the base Nos. 2, 8 



b Leaves very narrow, shorter than the culm. Glumes colored. . .Nos. 4 6 



b Leaves linear, longer than the culms. Glumes colored No. 7 



Glumes green Noa. 8 10 



b Leave? very broad, flat, with no midvein. Glumes scarious No. 11 



55 Staminate and pistillate flowers in the same (androgynous) spike. . . (c) 



ij Staminate and pistillate flowers in different spikes on the same culm. . .(i) 



on different culms No. 12 



c S Flowers variously situated in the approximate spikes Nos. (12 and) 13 15 



c X Flower* at the summit of the spikes. . .(at) 

 c t Flowers at the base of the spikes. . .(/) 



d Spikes GO, paniculate, brown ; perigynia corky, not rostrate Nos. 16, 17 

 d Spikes (or spikelets) 8 GO, approximate in a compound spike... (e) 



e Perigynium rostrate, scarcely longer than the glume Nos. 18 21 



e Periiryniuni long-rostrate, 2 or 3 times longer than tue gl Nos. 22, 23 



d Spikes 3 li. approximate into one ovoid spike Nos. 2426 



cylindric spike a little loose. .Nos. 27, 28 



d Spikes 3-8. remote. Perigynia erect in No. 32, radiating in Nos. 29 31 



f Perigyuia radiating in the 3 6 separated spikes. Glumes green. ...Nos. 33, 34 

 / Perig. stiberect. few (> 20) in each spikelet. Glumes hyaline white. . .(g) 

 f Perig. suberect. winged, 30 < ; in each oblong to ouovoid spikelet... (A) 



g Spkl. separate or remote. 2-3- flowered in No. 35, 5-20-flwd. in Nos. 3639 



g Spikclets clos-ely contiguous, i-12-flowered Nos. 40, 41 



A Perij_ r \nia lance-l.near. long-braked, 3 4". Spikelets close. Nos. 42 44 

 It Perigynia lanceolate, short-beaked. Spikelets 8 20, club-ovoid. No. 45 

 A Perigynia ovate, spreading. Spikilets round ovoid, close. .Nos. 4C, 47 

 li Ptrigrynia ronnd-obovate, short-beaked, broadly-winged. Five 



nominal species closely related and intermixed Nos. 48 52 



I Staminate spike single. Pistillate spikes sessile Nos. 53 56 



t Staminate spike single. Pistillate spikes pedunculate Nos. 57, f>8 



i Staminate spikes 1 or more, and the $ spikes often $ at the apex. ..(k) 



k Glumes obtuse, not exceeding the perigynia. Spikes sessile Nos. 59, 60 



k Gl. acute, little longer or shorter than periir. Lower spikes stalked, .(il 64 

 k Gl. long-awned. much exceeding the perig. Spikes all stalked. .Nos. 65 67 



iSJ Spikes an irogynotis. both kinds of fls. in each. t at the apex Nos. 68, 6!t 



S at the base No. 7H 



i Spikes the terminal 9 at top, the rest all pistillate. . .(/) 



$$$ Spike? the terminal on* wholly $ , the rest all pistillate.. (*) 



jt$$ Staminati- spikes habitually more than one. ..(**) 



/ (~pikes erect nr nearly so, grten, hairy in Nos. 71, 7i^ glabrous in. . . .Nos. 72 74 



I Spikes erect, pedunculate, tawny in maturity, glabrous Nos. 75, TO 



i Spikes erect (come nodding in No. 79) with black-purple glumes Nos. 77 79 



/ Spikes drooping on filiform stalks, green or some rusty. Nos. 80 SI 



P>t:'.;a:e spikes sessile, or solitary on radical peduncles. Perig. with 



a short abrupt beak, not inflated, pubescent. Culm slender. . ,(m] 



Pistillate spikes with enclosed or nearly enclosed peduncles. Perig. 



inflated, beaked, glabrous, bicuspidate at apex. Spikes turgid, 

 often quite large, their leafy bracts longer.. .() 



Pistillate spikes on exserted peduncles (exserted from the sheaths of 



24 



