50 CYPERACEAE (SEDGE FAMILY) 



CYPERACEAE (Sedge Family) 



Herbs, annual or perennial; rhizomes present; stems 3-angled 

 or terete, mostly solid. Leaves attenuate, mostly basal; sheaths 

 not split. Flowers in spikes or spikelets, small, perfect or monoe- 

 cious or dioecious, in the axils of scales; scales imbricate, 

 chaffy; spikes again variously grouped unless solitary. Peri- 

 anth none or of mere bristles or scales. Stamens usually 2-3, 

 hypogynous; anthers basifixed. Ovary i-celled; ovule i; style 

 2-3-cleft. Fruit an akene, lens-shaped or somewhat 3-angled, 

 membranous or crustaceous or bony. — A difficult family. Keys 

 only to the genera. (F. & R. pp. 74-89.) 



A. Akenes not inclosed in a saclike structure; flowers perfect; spikelets all alike. 

 B. Spikelets more or less flat; scales in 2 opposite rows. 



C. Stem nearly naked; leaves mostly basal; perianth none. — (Gk.. kupeiros = 

 the ancient name for these plants.) Cyperus (cypeeus) 



CC. Stem with 3 distinct rows of leaves; leaves mostly on the stem; perianth of 

 6-9 bristles. W. — (Gk. duo = 2, kichen = a scale; the scales of the spikelets 

 are in 2 ranks.) Dulichium anindinaceum (dulichium) 



BB. Spikelets terete; scales imbricated all round. 



D. Akenes not crowned with the bulbous base of the style. 

 E. Spikelets not a cottony mass. 



F. Perennial; perianth of 0-6 bristles. — One of these is S. occidenUUis (Tule), 

 whose stems are used for the interior of cheap life preservers. (The Latin 

 name of the Bulrush.) Scirpus (bulrush) 



FF. Annual; perianth of a single hyaline scale between the rachiUa and the 

 akene. — (Gk. hemi = half, karphos = chaff; because this genus has only 

 I inner scale while most related genera have 2 or more.) 



Hemicarpha (hemicaspha) 

 EE. Spikelets each a white to brown cottony head of hairs 1-3 cm. wide. — (Gk. 

 erion = wool or cotton, phoros = bearing; referring to the cottony spikes.) 



Eriophorum (cotton GEASs) 



DD. Akenes crowned with the persistent bulbous base of the style. 



G. Stem leafless; spikelets solitary, terminal; perianth bristles usually present, : 



0-12. — (Gk. elos = a marsh, chairo = to rejoice; because it grows in wet 



places.) Eleocharis (spike rush) 



GG. Stem leafy at least at base; spikelets more than i, in an involucrate umbel. 



H. Akene 3-angled; perianth bristles none. XT. — (Gk. stenos = narrow, 



phyllon = a leaf; on account of the very narrow leaves.) 



Stenophyllus capillaris (hair sedge) 



HH. Akene lens-shaped; perianth bristles 9-15, downwardly barbed. W. 



— (Gk. rhynchos = a snout, spora = a seed ; referring to the long-beaked 



akene.) Rhynchospora alba (white beak-rush) 



AA. Akenes inclosed in a saclike structure; flowers monoecious; spikes mostly of 



2 kinds. — (Gk. keirein = to cut; referring to the sharp leaf-edges.) 



' Carez (sedge) 



