Genus 2. 



SEDGE FAMILY. 



3°7 



28. Cyperus refractus Engelm. Reflexed Cyperus. Fig. 748. 



C. refractus Engelm.; Boeckl. Linnaea 36: 369. 1869-70. 



Perennial by tuber-like corms, culm stout, smooth, 

 i°-3° tall. Leaves 2¥'-a" wide, rough-margined, 

 elongated; umbel 6-13-rayed, usually compound, the 

 longer rays sometimes 8' long, their sheaths terminat- 

 ing in 1 or 2 short teeth; involucels setaceous; raylets 

 filiform; spikelets very narrowly linear, loosely spicate, 

 acute, flattish, 5"-i2" long, i" thick, 3-6-flowered, the 

 upper spreading, the lower reflexed; scales yellowish- 

 green, oblong-lanceolate, obtuse, closely appressed, 

 9-11-nerved, thin; stamens 3; style 3-cleft, its branches 

 much exserted; achene narrowly linear, obtuse, apicu- 

 late, about 5 times as long as thick, and one-half as 

 long as the scale. 



In dry fields, New Jersey to Georgia, Missouri and Texas. 

 July-Sept. 



29. Cyperus retrofractus (L.) Torr. Rough Cyperus. Fig. 749. 



Scirpus retrofractus L. Sp. PI. 50. 1753. 



Cyperus retrofractus Torr. ; A. Gray, Man. 519. 1848. 



Cyperus dipsaciformis Fernald, Rhodora 8: 127. 1906. 



Perennial by tuber-like corms, culm slender, rough- 

 puberulent, at least above, mostly longer than the pu- 

 berulent leaves, l°-3° tall. Leaves \\"-2.\" wide, those 

 of the involucre 4-7, the longer not greatly exceeding 

 the umbel; umbel simple; rays very slender, nearly 

 erect, or spreading, 2'-6' long, their sheaths 2-toothed ; 

 heads oblong or obovoid; spikelets linear-subulate, 

 3"-6" long, about i" thick, 1-3-flowered, all soon 

 strongly reflexed ; flowering scales lanceolate, acute, 

 the upper one subulate, all strongly several-nerved; 

 stamens 3; style 3-cleft; achene linear, 3-angled, obtuse, 

 apiculate, two-thirds as long as the scale. 



In dry, sandy soil, southern New Jersey to Florida, west 

 to Kentucky, Missouri and Texas. July-Sept. 



30. Cyperus lancastriensis Porter. Lancaster Cyp erus. Fig. 750. 



C. lancastriensis Porter; A. Gray, Man. Ed. 5, 555- 1867. 



Perennial by ovoid or oblong corms, culm slender, 

 smooth, mostly longer than the leaves, i°-2i° tall. 

 Leaves z"-3" wide, those of the involucre 4-7, the 

 longer much exceeding the inflorescence; umbel simple, 

 5-9-rayed, the longer rays 2'-4' long, their sheaths 

 nearly truncate; heads oval, obtuse, J'-i' long; spike- 

 lets densely clustered, 4"~S" l° n g> linear, subterete, 

 2-4-flowered, the lower reflexed, the middle ones spread- 

 ing, all separating from the axis at maturity; scales 

 green, strongly several-nerved, the flowering ones lan- 

 ceolate, subacute; stamens 3; style 3-cleft; achene 

 linear, obtuse, apiculate, 2-3 times as long as thick, 

 two-thirds as long as the scale. 



In dry fields, New Jersey and Pennsylvania to Georgia, 

 Missouri and Alabama. July-Sept. 



