234 CYPERACEAE. 
| Family 8. CYPERACEAE J. St. Hil. Expos. Fam. 1: 62. 1805. 
SEDGE FAMILY. 
Grass-like or rush-like herbs. Stems (culms) slender, solid (rarely hollow), 
triangular, quadrangular, terete or flattened. Roots fibrous (many species per- 
ennial by long rootstocks). Leaves narrow, with closed sheaths. Flowers per- 
fect or imperfect, arranged in spikelets, one (rarely 2) in the axil of each scale 
(glume, bract), the spikelets solitary or clustered, 1-many-flowered. Scales 2- 
ranked or spirally imbricated, persistent or deciduous. Perianth hypogynous, 
composed of bristles, or interior scales, rarely calyx-like, or entirely wanting. 
Stamens 1-3, rarely more. Filaments slender or filiform. Anthers 2-celled. 
Ovary 1-celled, sessile or stipitate. Ovule 1, anatropous, erect. Style 2-3- 
cleft or rarely simple or minutely 2-toothed. Fruit a lenticular plano-convex 
or trigonous achene. Endosperm mealy. Embryo minute. 
About 65 genera and 3000 species, ef very wide geographic distribution, The dates given be- 
low indicate the time of perfecting fruit. 
Flowers of the spikelets 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. 
Spikelets with 2-several perfect flowers; scales several to numerous. 1. Cyperus. 
Spikelets with but 1 perfect flower; scales 2-4. 2. Kyllinga. 
Perianth of 6-9 bristles; inflorescence axillary. 3. Dulichtum. 
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. 
Teaves reduced to basal sheaths; bristles usually present; spikelet solitary. 
4. Eleocharis. 
Culm leafy; bristles none; spikelets 1-numerous. 
Spikelets capitate, involucrate. 5. Dichromena. 
Spikelets umbellate or cymose. 
Spikelets in terminal and axillary compound cymes; most of the style per- 
sistent. 6. Pstlocarya. 
Spikelets in a terminal umbel, base of style persistent. 7. S/enophyllus. 
Base of the style enlarged or narrow, deciduous. 
Flowers with no broad sepals nor interior perianth-scales. 
Style swollen at the base; bristles none. 8. Fimbrisivlis. 
Style not swollen at the base; bristles usually present. 
Spikelets solitary-many; bristles 1-6, rarely none. 9. Scirpus. 
Spikelets solitary or few; bristles 6-many, soft, smooth, very long, slender, 
much exserted. 10. Eriophorum. 
Flowers with a perianth of 3 stalked sepals or of 1 or 2 interior hyaline scales. 
“3 Perianth of 3 broad stalked sepals, usually alternating with as many bristles. 
11. Futrena. 
Perianth of 1 or 2 hyaline scales (sepals?); bristles none. 
Perianth of a single minute posterior scale. 12. Hemicarpha. 
Perianth of 2 scales, convolute around the ovary. 13. Lipocarpha. 
Spikelets 1-4-flowered, some of the flowers imperfect. 
Style, or its base, persistent as a tubercle on the achene. 14. Rynchospora. 
Style wholly deciduous. 15. Cladium. 
Flowers all monoecious or dioecious, usually borne in separate small spikelets. 
Achene not enclosed in a utricle (perigynium). 
Spikelets clustered or solitary, not in a terminal spike; achene bony. 16. Scleria. 
Spikelets forming a terminal spike; arctic genera. 
Scales 2-flowered, androgynous. 17. Elyna. 
Scales 1-flowered, monoecious. 18. Kobresia. 
Achene enclosed in a utricle (perigynium). ; 
Axis of the pistillate flower conspicuous, subulate, often exserted beyond the perigynium. 
19. Uncinia. 
Axis of the pistillate flower rudimentary or none, not exserted. 20. Carex. 
1. CYPERUS L. Sp. Pl. 44. 1753. 
Annual or perennial sedges. Culms in our species simple, triangular, leafy near the 
base, and with 1 or more leaves at the summit, forming an involucre to the simple or com- 
pound, umbellate or capitate inflorescence. Rays of the umbel sheathed at the base, 
usually very unequal, one or more of the heads or spikes commonly sessile. Spikelets flat 
or subterete, composed of few or many scales, the scales falling away from the wingless or 
winged rachis as they mature (nos. I-Ig), or persistent and the spikelets falling away 
from the axis of the head or spike with the scales attached (nos. 20-32). Scales concave, 
conduplicate or keeled, 2-ranked, all flower-bearing or the lower ones empty. Flowers per- 
fect. Perianth none. Stamens 1-3. Style 2-3-cleft, deciduous from the summit of the 
lenticular or 3-angled achene. [Ancient Greck name for these sedges. ] 
_ About 650 species, of wide distribution in tropical and temperate regions. Besides the follow- 
ing, some 4o others occur in the southern United States. The English names Galingale and Sweet 
Rush are sometimes applied to all the species. 
