CYPEBACEAE. 57 



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

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

 ton- (P.). 



Burlington-* Ameytown (C). Mercer— Princeton (Te.). 



$ew Castle— Frequent. 



68. AKUNDINABIA Michx. 

 1. Arundinaria tecta (Walt.) Muhl. Switch Cane, Small Cane. M. p. 

 158. Swamps aid moist soil. Summer. 

 Delaware — Painter's Arboretum (He.). 



Family 2. CYPERAOEAE 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. 



, ,i, , 1. Cyperus. 



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

 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 leafy; perianth-bristles, none; spikelets in a ter- 

 minal umbel. 4. fitenophyllus. 

 Base of the style enlarged or narrow, deciduous. 



Flowers with np 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 

 i none. '" , , 6. Scirpus. 



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

 smooth, very long, slender, much exserted. 



7. Eriophomm. 

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

 interior hyaline scales. 8. Fuirena. 



Spikelets 1-4-flowere'd, 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 dioecious, 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 yellow; superficial cells of the achene oblong. 



■! " ' 1. C. flavescens. 



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

 Scales obtuse or obtusish, appressed. 



Scales membranous^ dull; style much exserted. 



2. C. diandms. 

 Scales subcoriaceous, shining;, style scarcely exserted. 



, 3. C. rivularis., t 

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



