46 



CYPEKACEAE. 



7. Cypenis esculentus L. Yellow 

 Nut-grass. (Fig. 67.) Perennial by 

 scaly tuber-bearing rootstocks; culm 

 usually stout, l°-3° tall, shorter than the 

 leaves or longer. Leaves light green, 2"- 

 4" wide, the midvein prominent; those 

 of the involucre 3-6, the longer much 

 exceeding the inflorescence ; umbel 4-10- 

 rayed, often compound; spikelets numer- 

 ous in loose spikes, straw-color or yellow- 

 ish-brown, flat, spreading, i'-l' long, 

 about ly wide, many-flowered; scales 

 ovate-oblong, subacute, 3-5-nerved ; rachis 

 narrowly winged ; stamens 3 ; style 3- 

 cleft; achene obovoid, obtuse, 3-angled. 



Occasional in cultivated grounds. Na- 

 tive. United States, West Indies, tropical 

 continental America, tropical and temperate 

 regions of the Old World. Flowers in sum- 

 mer and autumn. 



8. Cyperus altemifolius L. Umbrella 

 Sedge. (Fig. 68.) Perennial by short root- 

 stocks, glabrous; culms stout, clustered, 3°- 

 4^° high, smooth and 3-angled. Basal leaves 

 reduced to lanceolate sheaths; leaves of the 

 involucre 12-20, spreading, 10' long or less, 

 2'''-5" wide, longer than the inflorescence; 

 umbel decompound, often 8' broad; rays 

 numerous, nearly filiform; heads very 

 numerous; spikelets few, digitate, linear, 

 many-flowered, blunt, 4' -5" long, about 1" 

 wide; scales greenish-yellow, lanceolate, 

 acute, appressed; achene oblong, a little 

 shorter than the scale. 



Occasional in marshes and along roads. 

 Introduced by cultivation as an ornamental 

 sedge, and escaped. Native of Africa. Flowers 

 from spring to autumn. Naturalized in the 

 West Indies. 



Cyperus Papyrus L., Papyrus, Egyptian, successfully grown for six years 

 in a tub at Orange Valley, and observed there in 1914, is a very large sedge, 

 with 3-sided culms, 7°-9° high, the numerous, nearly filiform leaves of the 

 involucels 8'-12' long. 



2. KYLLINGA Eottb. 



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 1 or 2 lower ones small and empty, the middle one fertile, the upper 

 empty or staminate. Joints of the rachis wingless or narrowly winged. 

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

 uous from the summit of the achene. Achene lenticular or 3-angled. [In 

 honor of Peter Kylling, a Danish botanist of the seventeenth century.] About 

 45 species, natives of tropical and temperate regions. Type species: KylUnga 

 monocepTiala Eottb. 



