490 CYTERACE.E. (sedge family.) 



Order 133. CYPERACKiE. (Sedge Family.) 



Grass-like or rush-like herbs, with Jibrous roots and solid stems (culms), 

 closed sheaths, and spiked chiefly B-androlis flowers, one in the axil of each 

 of the glume-like imbricated bracts (scales, glumes), destitute of any perianth, 

 or with hypogynous bristles or scales in its place; the l-celled ovary with a 

 single erect anatropous ovule, in fruit forming an achenium. Style 2-cleft 

 when the fruit is flattened or lenticular, or 3-cleft when it is 3-ansmlar 

 Embryo minute at the base of the somewhat floury albumen. Stem-leaves 

 when present 3-ranked. — A large, widely diffused family. See Addend. 



Synopsis. 



Tribe I. CYPEREjE. Flowers perfect, 2-ranked. Spikelets 1 - many-flowered. 



1. CYPEKUS. Spikes few -many-flowered, usually elongated or slender. Perianth none. 



2. KYLL1NGIA. Spikes 1-flowered, glomerate in a sessile head. Perianth none 



3. DULIOIIIUM. Spikes 6-10 flowered. Perianth of 6 - 10 bristles Achenium beaked. 



Tribe II. HYPOLYTRES;. Flowers perfect ; the scales many-ranked : each flower 

 provided with its own (1 - 4) proper scale-like bractlets True perianth none. 



4. HEMICARPHA. Bractlet or inner scale 1, very small. Stamen 1. Style 2-cleft. 



Tribe III. SCIRPE^S. Flowers perfect ; the scales regularly several-ranked, each cov- 

 ering a naked flower, or only the lowest empty. Perianth of bristles or hairs, or none. 

 * Perianth of hypogynous bristles or hairs (rarely obsolete or wanting). 



5. ELEOC1IARIS. Achenium with a tubercle jointed on its apex, consisting of the bulbous 



persistent base of the style. Head solitary, terminating the leafless and braetless culm. 



6. SCIRPUS. Achenium naked at the apex or pointed with the continuous simple base of 



the style. Perianth of 3 - 6 bristles. Culms leafy at the base Heads one or more. 



7. ERIOPHOIIUM. Achenium, &c, as in Scirpus. Perianth of long and tufted woolly hairs. 



* * Perianth none. 



8. FIMBRISTYLIS. Style bulbous at the base, deciduous (with or rarely without the jointed 



bulb) from the achenium. 



* # # Perianth of 3 large scales, and mostly as many alternating bristles. 

 S). FDIltENA. Scales of the spike awned below the apex Achenium triangular, pointed 

 with the base of the style. 



Tribe IV. RKYKt'HOSPORE^. Flowers perfect or polygamous. Scales of the 

 few-flowered spikes irregularly several-ranked, many of t:.e lower ones empty, and often 

 the upper sterile. Perianth of bristles or none Stems leafy. 



* Achenium beaked with the dilated persistent style or its base. 

 +- Perianth none : style 2-cleft : achenium wrinkled transversely. 



10. PSILOCARYA. Spikes many-flowered, terete, ovoid, cymose, naked. 



11. DIOIIROMENA. Spikes few-flowered, flattened, crowded into a leafy-involucrate head. 



*- +- Perianth of bristles or awns, rarely wanting 

 12 CERATOSCIKENUS. Style simple, all persistent in the awned beak of the flat achenium. 

 13. R11YN0IIOSPORA. Style 2-cleft, the base only persistent as a tubercle on the achenium. 



* * Achenium without a beak or tubercle ; the style deciduous. 



II. CLADIUM. Achenium globular, corky or pointed at the summit. Perianth none. 



Tribe V. SCLKItlKiE. Flowers monoecious : the fertile spikes 1-flowered ; tlin stain 

 inate several-flowered. Achenium nut-like, mostly crustaceous. 



15 S'JLERIA. Achenium bony or crustaceous. Proper perianth none 



