Carcx.] LXXXVIII. CYPERACE^. 489 



fl / Terminal spikelet male at the base. Spike simple ...... 7 



\Terminal spikelet male at the top. Spike often branched or compound. . IS 

 ( Spikelets forming a terminal spike without leafy bracts, or with only a small 



7 one to the lowest spikelet . . 8 



(Spikelets very distant, the lower ones each in the axil of a long leafy bract . 12 

 ( Spikelets ovoid, close together. Fruits tapering to a point, erect or scarcely 



8 spreading 9 



( Spikelets, at least the lower ones, at some distance from each other . . 10 



Q( Fruits winged at the edges. Stems usually a foot high or more 5. C. leporina. 



\Fruitsnotwinged. Stems usually 8 or 9 inches high . . 6. C. lagopina. 



( Fruits tapering to a point or beak considerably longer than the glume . . 11 



10 \ Fruits erect, ovate, with a minute point. Stems a foot or more. Spikelets 



( pale green 9. C. canescens. 



(Ripe spikelets nearly globular, with very spreading beaked fruits. Stem 6 or 

 8 inches 8. C. steUulata. 

 Ripe spikelets oblong, with rather spreading pointed fruits. Stem 1 to 2 feet. 

 7. C. elongata. 



( All the spikelets simple, sessile, and distant . . . 10. C. remota. 



12 ( Lower spikelets branched or 2 or 3 together. Upper ones rather near together. 

 ( 11. C. axillaris. 



./ Stems tufted, without creeping rootstocks 14 



\Rootstocklongandcreeping 18 



i Spike compound or branched. Stems 1 to 4 feet (usually 2 to 3 feet) . . 15 

 14 \ Spike simple or the lower spikelets slightly compound. Stems not a foot or 

 ( very slender . . . 16 



{Spike or panicle dark brown, rather loose. Fruits obtusely 3-angled. 

 12. C. paniculata. 

 Spike cylindrical, often green, densely crowded. Fruits much flattened, with 

 acute angles. Stem acutely triangular 13. C. vulpina. 



( Spikelets near together, iu a terminal brown spike about an inch long. 

 16-1 14. C. muricata. 



( Lower spikelets distant, all pale brown or green 17 



( Fruiting spikelets globular, no male flowers at their base . . 14. C. muricata. 



17 < Fruiting spikelets oblong, a few males at the base of some of them. Fruits 



( flattened 11. C. axillaris. 



( Spikelets rather large, ovoid, in a spike of 1 or 2 inches. Fruits with a very 



18 \ thin or winged edge 15. C. arenaria. 



( Spikelets short, in a spike of about i inch. Fruit very convex, not winged . 19 

 ( Spike ovoid, the spikelets distinct. Stem slender, erect . . 16. C. divisa. 



19 < Spike nearly globular, very dense. Stem short, curving downwards. 



( 17. C. incurva. 



^/Spikelets short, erect 21 



\ Spikelets oblong or cylindrical, stalked and drooping 22 



Spikeleta at length rather distant, the lowest scarcely stalked. Fruit ovoid, 



obtuse 22. C. Buxbaumii. 



Spikelets close together, the lowest stalked. Fruit angular, shortly beaked. 



21. C. alpina. 



( Spikelets oblong, very black. Fruit triangular, with a short beak 23. C. atrata. 

 22 < Spikelets cylindrical, green. Glumes and fruits with long subulate points. 

 ( 43. C. Pseudocyperus. 



Spikelets several, one or more terminal ones wholly male. 

 23/ Stigmas 2 24 



( Spikeleta small, green, and distant, lower one branched or clustered. 

 24 X 11. C. axillaris. 



( Spikeleta cylindrical or oblong, few, dark-brown or black 25 



,/ Fruits very convex or inflated 18. C. saxatilis. 



M \Fruita nearly flat 26 



Glumes mostly obtuse. Spikeleta i to 2 inches long . . .19. C. ccespitosa. 

 Glumes mostly narrow and pointed. Female spikelets 3 inches or more. 



20. C. acuta. 



Bracts sheathing, without leafy tips. (Fruits obtuse, slightly downy) . . 28 

 Bracts, at least the lower ones, leafy, with or without sheaths . . . .29 

 Stems shorter than the leaves. Female spikelets short, distant, half-included 



in the sheaths 24. C. humilis. 



Stems longer than the leaves. Female spikelets near the top, linear, spreading. 



25. C digitata. 



