84 CYPERACEAE (SEDGE FAMILY) 



flexuous or somewhat nodding: spikelets usually 2 at each node: glumes 

 setaceous, divaricate; lemma scabrous, tipped with a stout scabrous awn 5-6 

 cm. long. New Mexico to Wyoming and westward. 



2. Sitanion brevifolium J. G. Smith, 1. c. 17. Tufted, 2-4 dm. high: culms 

 faintly striate, glaucous: innovations not more than half the length of the 

 culms: sheaths smooth; leaves flat or involute, 5-10 cm. long, smooth be- 

 neath, subscabrous above: spike long-exserted: glumes divergent, 5-9 mm. 

 long, scabrous above; lemma 8-10 mm. long, linear-lanceolate, tipped with a 

 stout scabrous awn 4-8 cm. long; palet obtuse, as long as its lemma. The fol- 

 lowing, published in the revision of the genus by J. G. Smith, do not seem 

 readily separable from this species, at least in so far as the plants of our range 

 are concerned: S. vubeflorum, S. rigidum, S. glabrum. 



3. Sitanion hystrix (Nutt.) J. G. Smith, 1. c. 15. Softly and minutely 

 pubescent, low, 1-3 dm. high, in dense spreading tufts: innovations very 

 leafy, about half as long as the culms: leaves flat or at length involute, promi- 

 nently 9-nerved, erect or ascending, 7-12 cm. long: spikes 5-7 cm. long: 

 spikelets 3-4-flowered: glumes bifid, unequally 2-awned, the awns divergent, 

 3-4 cm. long; lemma 7-8 mm. long, 3-awned, the middle awn slender, re- 

 curved; palet 2-awned. In the desert areas of our range, especially in dry 

 saline soils. 



4. Sitanion montanum J. G. Smith, 1. c. 16. Culms 2-4 dm. high, scabrous 

 above: sheaths and leaves more or less finely scabrous; blades 5-10 cm. long: 

 spike 5-10 cm. long: glumes subulate, scabrous, long-awned; lemma 10-11 mm. 

 long, linear-lanceolate, scabrous above, trifid, 3-awned; the middle awn 4-7 

 cm. long; the two lateral quite short and slender. (S. molle J. G. Smith, 1. c. 

 17.) This may be the original of Rafinesque's Sitanion elymoides (Elymus 

 Sitanion Schult.), but this is mere conjecture. The segregates of Sitanion 

 elymoides, a few of which have been here given, are none too distinct, and it 

 is perhaps better to retain the old name for the group. Frequent; Wyoming 

 and Montana to Oregon. 



17. CYPERACEAE J. St. Hil. SEDGE FAMILY 



Grass-like or rush-like herbs. Stem leaves when present 3-ranked. Stems 

 (culms) usually solid, triangular, quadrangular, flattened or terete. Leaves 

 with closed sheaths, mostly narrow. Flowers perfect or imperfect, arranged 

 in spikelets one in the axil of each scale (glume, bract) ; the spikelets solitary 

 or in spicate clusters. Scales 2-ranked or spirally imbricated. Perianth 

 wanting or of hypogynous bristles (rarely calyx-like). Stamens 1-3. Styles 

 2-3. Fruit a lenticular or trigonous achene. 



Flowers perfect; the spikes capitate or umbellate. 



Spikelets flattened, with the scales in 2 ranks; perianth wanting. 1. Cyperus. 



Spikelets not flattened, the imbricated scales all around; perianth, 



in the form of bristles, usually present. 

 Stamens mostly 3; perianth of 1-several bristles. 

 Bristles few and short, at the base of the achene. 



Leaves (at least the basal) well developed 2. Scirpus. 



Leaves reduced to only a sheathing base ... 3. Eleocharis. 



Bristles many, long-exserted 4. Eriophorum. , 



Stamens 1 ; perianth wanting 5. Hemicarpha. 



Flowers imperfect (monoecious or dioecious); spikelets solitary, spicate 

 or paniculate. 



Achene naked 6. Elyna. 



Achene inclosed in an inflated sac-like persistent perigynium 7. Carex. 



1. CYPERUS L. 



Mostly with triangular and nearly naked simple stems, sheathed at baSe by 

 the nearly radical leaves. Inflorescence subtended by a mostly conspicuous 

 leafy involucre, usually irregularly umbellate with unequal rays, the spikelets 



