CYPEBACEAE. 57 



Khoads' Swamp, Marple (B. Sm.), Concord (W. Tr.). Chester— St. 

 Peter's (Ke.), Brandywine Creek (Pr.). Lancaster— {F.). Northamp- 

 ton- (P.). 



Burlington— Amejtovyn (C.)- i/ercer— Princeton (Te.)- 



New Castle — Frequent. 



68. ARUNDINAPJA Michx. 

 1. Aeundinaria tecta (Walt.) Miihl. Switch Cane, Small Cane. M. p. 

 158. Swamps and moist soil. Summer. 

 Delaware — Painter "s Arboretum (He.). 



Family 2. CYPERACEAE J. St. Hil. Sedge Family. 



Flowers of the spikelet all, or at least one of them, perfect; spikelets all 

 similar. 

 Scales of the spikelets 2-ranked. 



Perianth none ; spikelets in solitary or umbelled terminal heads. 



1. Cyperus. 

 Perianth of 6-9 bristles ; inflorescence axillary. 2. Dulichium. 

 Scales of the spikelets spirally imbricated all around. 

 Spikelets with several to many perfect flowers. 



Base of the style swollen, persistent as a tubercle on the 

 achene. 

 Leaves reduced to basal sheaths; bristles of the perianth 



usually present ; spikelet solitary. 3. Eleocharis. 



Culm leafj' ; perianth-bristles none ; spikelets in a ter- 

 minal umbel. 4. Stenophyllus. 

 Base of the style enlarged or narrow, deciduous. 



Flowers with no broad sepals or interior perianth-scales. 

 Style swollen at the base; bristles none. 



5. Fimbristylis. 



Style not swollen at the base; bristles usually present. 



Spikelets solitary to many; bristles 1-6, rarely 



none. 6. Scirpus. 



Spikelets solitary or few; bristles 6-mauy, soft, 

 smooth, very long, slender, much exserted. 



7. Eriophorum. 

 Flowers with a perianth of 3-stalked sepals or of 1 or 2 

 interior hyaline scales. 8. Fuirena. 



Spikelets 1-4-flowered, some of the flowers imperfect. 



Style, or its base, persistent as a tubercle on the achene. 



9. Eynchospora. 

 Style wholly deciduous. 10. Cladium. 



Flowers all monoecious or dicecious, usually borne in separate small spikelets. 

 Achene not enclosed in a utricle. 11. Scleria. 



Achene enclosed in a utricle (perigynium). 12. Carex. 



1. CYPERUS L. Galingale. 



Style 2-cleft ; achene lenticular, not 3-angled; scales falling from the rachis; 

 spikelets flat. 

 Spikelets yeUow; superficial cells of the achene oblong. 



1. C. fiavescens. 

 Spikelets green or brown; superficial cells of the achene quadrate. 



Scales obtuse or obtusish, appressed. 



Scales membranous, dull; style much exserted. 



2. C. diandrus. 

 Scales subcoriaceous, shining; style scarcely exserted. 



3. C. rivularis. 

 Scales acute, somewhat spreading at maturity. 4. C. Nuttallii. 



