SEDGE FAMILY 



259 



9. Cyperus vegetus W'illd. 

 Tall Cyperus. Fig. 616. 



Cyperus vegetus Willd. Sp. PI. 1: 283. 1797. 



Cyperus serrnlaius S. Wats. Proc. Am. Acad. 17: ii-l. 1882. 



Perennial by rootstocks. Culms sometimes thickened 

 at the base, smooth, stout, 3-10 dm. tall ; basal leaves as 

 long as the culm or shorter, 10 mm. wide or less, more or 

 less transversely lineolate, those of the involucre several, 

 similar to the basal ones, the longer much exceeding the 

 compound umbel; umbel-rays 2-10 cm. long; spikelets 

 several to many, flat, digitate, 10-18 mm. long, about 3 mm. 

 wide; scales ovate or ovate-lanceolate, yellow or yellowish 

 white, the keel sometimes serrulate ; stamen 1 ; achene 

 oblong. 



Moist soil, Upper Sonoran Zone; central and south central Cali- 

 fornia, north to IJutte County; San Luis Potosi to Mexico; west- 

 ern South America. The California plant has been referred to C. 

 vircns Mich.x. Type locality not cited. 



10. Cyperus esculentus L. 



Yellow Nut-grass. Fig. 617. 



Cyperus esculentus L. Sp. PI. 45. 1753. 



Cyperus phymatodes Muhl. Gram. 23. 1817. 



Cyperus h'ermauni Buckley, Proc. Acad. Phila. 1862: 10. 



1862. 

 C. esculentus inacrostachyus Boeckl. Linnaea 36: 291. 1869. 

 C. phymatodes hcrmanni S. Wats. Bot. Calif. 2: 215. 1880. 

 C. esculentus hermanni Britton, Bull. Torrev Club 13: 211. 



1886. 



Perennial by scaly tuber-bearing rootstocks ; culm 

 usually stout, 0.3-0.8 m. tall, commonly shorter than 

 the leaves. Leaves light green, 4-8 mm. wide, the 

 midvein prominent, those of the involucre 3-6, the 

 longer much exceeding the inflorescence ; umbel 4-10- 

 rayed, often compound ; spikelets numerous in loose 

 spikes, straw-color or yellowish brown, flat, spread- 

 ing, 1-2.5 cm. long, about 3 mm. wide, many-flowered, 

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

 narrowly winged; stamens 3; style 3-cleft ; achene 

 obovoid, obtuse, 3-angled. 



Fields and banks, Canadian to Sonoran Zone; southern 

 California to Washington; Alaska; eastward across the con- 

 tinent to Florida and New Brunswick; tropical America and 

 widely distributed in the Old World. Consists of many races. 

 Type locality: Montpellier, France. 



11. Cyperus rotundus L. 



618. 



Nut-grass. 



Fig. 



Cyperus rotundus L. Sp. PI. 45. 1753. 



Perennial by scaly tuber-bearing rootstocks, culm 

 rather stout, 1.5-5 dm. high, usually longer than the 

 leaves. Leaves 3-6 mm. wide, those of the involucre 

 3-5, the longer equaling or exceeding the inflor- 

 escence; umbel compound or nearly simple, 3-8-rayed, 

 the longer rays 5-12 cm. long; spikelets linear, closely 

 clustered, few in each cluster, acute, 8-20 mm. long, 

 2-3 mm. wide ; scales dark purple-brown or with 

 green margins and center, ovate, acute, closely 

 appressed when mature, about 3-nerved on the keel ; 

 stamens 3; style 3-cleft, its branches exserted; achene 

 3-angled, about one-half as long as the scale. 



Local in southern California, becoming a weed, appar- 

 ently recently naturalized. Widely distributed in the east- 

 ern L^nited States and in temperate and tropical regions of 

 both the Old World and the New. Type locality: India. 



