296 



CYPERACEAE. 



VOL. I. 



About 75 genera and 3200 species, widely distributed. The dates give time of perfecting fruit. 



* Fertile flowers perfect. 



t Basal empty scales of the spikelets none, or not more than 2 (except in Eriophorum}. 

 Scales of the spikelets 2-ranked ; bristles none. 



Spikelets with only i perfect flower. i. Kyllinga. 



Spikelets with 2 to many perfect flowers. 2. Cyperus. 



Scales of the spikelets spirally imbricated. 



Base of the style persistent as a tubercle on the achene. 



Spikelet i ; culm leafless ; bristles usually present. 3. Eleocharis. 



Spikelets several or numerous ; culms leaf-bearing ; bristles none. 4. Stenophyllus. 



Base of the style not persistent as a tubercle. 

 Flowers without any inner scales. 



Base of the style swollen ; bristles none. 5. Fimbristylis. 



Base of the style not swollen ; bristles usually present. 



Bristles 6 to many, silky, much elongated. 6. Eriophorum. 



Bristles short, or little elongated, smooth or barbed. 7. Scirpus. 



Flowers with i or more inner scales. 



Flowers with 3 broad, stalked scales alternating with barbed bristles. 8. Fuirena. 

 Flowers with i or 2 hyaline scales ; bristles none. 



Flowers with 2 convolute inner scales. 9. Lipocarpha. 



Flowers with a single minute inner scale. 10. Hemicarpha. 



tt Basal empty scales of the spikelets 3 or more. 

 Style 2-cleft. 



Spikelets breaking up into i-fruited joints; bristles present; scales 2-ranked. u. Dulichium. 

 Rachis of the spikelets not jointed, persistent ; scales spirally imbricated. 



Spikelets flattened, clustered in a single involucrate head; bristles none. 12. Dichromena. 

 Spikelets not flattened, variously clustered. 



Spikelets few-flowered ; bristles usually present. 13. Rynchospora. 



Spikelets many-flowered; bristle none. 14. Psilocarya. 



Style 3-cleft ; bristles none. 15. Mariscns. 



** All the flowers imperfect. 



Pistillate flower subtended by a flat scale ; achene bony. 16. Scleria. 



Pistillate flower enclosed in a perigynium or enwrapped by a concave or convolute scale. 



Pistillate flower partly enwrapped by a scale. 17. Kobresia. 



Pistillate flower wholly enclosed by a perigynium. 



Leaves more than one, with sheath, ligule and midvein. 18. Carex. 



Leaf one, without sheath, ligule or midvein. 19. Cymophyllus. 



i. KYLLINGA Rottb. Descr. & Ic. 12. pi 4. f. 3, 4. 1773. 



Annual or perennial sedges, with slender triangular culms, leafy below, and with 2 or 

 more leaves at the summit forming an involucre to the strictly sessile, simple or compound 

 dense head of spikelets. Spikelets numerous, compressed, falling away from the axis of 

 the head at maturity, consisting of only 3 or 4 scales, the I or 2 lower ones small and empty, 

 the middle one fertile, the upper empty or staminate. Joints of the rachis wingless or nar- 

 rowly winged. Scales 2-ranked, keeled. Perianth none. Stamens 1-3. Style 2-cleft, decid- 

 uous from the summit of the achene. Achene lenticular. [In honor of Peter Kylling, a 

 Danish botanist of the seventeenth century.] 



About 45 species, natives of tropical and temperate regions. Besides the following, 2 others 

 occur in the southern United States. Type species : Kyllinga monocephala Rottb. 



i. Kyllinga pumila Michx. Low Kyl- 

 linga. Fig. 720. 

 Kylllngia pumila Michx. Fl. Bor. Am. i : 28. 1803. 



Annual, culms densely tufted, filiform, erect 

 or reclined, 2'-!$' long, mostly longer than 

 the leaves. Leaves light green, roughish on 

 the margins, usually less than i" wide, those 

 of the involucre 3-5, elongated, spreading or 

 reflexed; head oblong or ovoid-oblong, 3"-4" 

 long, simple or commonly with I or 2 smaller 

 ones at the base; spikelets about il" long, 

 flat, i-flowered, the 2 empty lower scales more 

 or less persistent on the rachis after the fall 

 of the rest of the spikelets ; scales ovate, acumi- 

 nate or acute, thin, about 7-nerved, the fertile 

 one with a rough keel; stamens 2; style 2-cleft ; 

 achene lenticular, obtuse. 



In moist or wet soil, Delaware to Florida, Illi- 

 nois, Kansas, Texas and Mexico ; West Indies and 

 tropical continental America. Aug.-Sept. 



