70 POACEAE 



58. CATABROSA Bcaiiv. Brook-graSS: 



Creeping or floating aquatic perennial. Panicles open, with slender spread- 

 ing or reflexed branches. Spikelets 2- (rarely 3- or 4-) flowered, with the rachilla 

 articulate between the flowers. Empty glumes unequal, broad, thin, very ob- 

 tuse. Lemma strongly 3-nerved, longer than the empty glumes. Palet 2- 

 keeled, nearly as long. Styles distinct; stigmas plumose. 



1. C. aquatica (L.) Beauv. Stem 1-3 dm. high, bright green, flaccitl; leaf- 

 blades 3-12 cm. long, 2-6 mm. wide, flat, obtuse; panicle 3-20 cm. long, open; 

 branches whorled; spikelets 2.5-3.5 mm. long; first glume about 1 mm., the 

 second nearly 2 mm. long; lemma 2-2.5 mm. long, 3-nerved, erose-truncate at 

 the apex. In water: Lab. — (^ue. — Colo. — Utah — ^Alaska; Eurasia. Subrnont- 

 Subalp. Je-Au. 



59. SPHENOPHOLIS Scribn. 



Tall tufted perennials. Panicles usually narrow. Spikelets numerous, 2-3- 

 flowered, shining. First emi)ty glume narrow, 1-nerved, acuminate, the second 

 much broader, obovate when spread, obtuse or truncate, 3-nerved. Lemma 

 narrower than the second glume, obtuse or acute. Palet narrow, 2-nerved. 

 Styles short; stigmas i)lumose. [Eatonia Raf.] 



Second empty glume much wider than the lemma, rounded or truncate and somewhat 

 cucullate at the apex. 

 Intermediate nerves of the second glume almost as prominent as the lateral ones; 

 leaf-blades firm, much broader than the sheaths and therefore with prominent 

 auricles. 1. S. rohusta. 



Intermediate nerves of the second glume faint, the lateral ones strong; leaf-blades 

 soft, not much wider than the sheaths; auricles not prominent. 2. S. oblusata. 

 Second empty glume oblanceolate, not much wider than the lemma, obtuse or acute. 

 Second empty ghune rather firm, as well as the lemma obtusish. 3. S. intermedia. 

 Second empty glume tliin and with a broad, scarious margin, acutish; lemma acute. 



4. S. pollens. 



1. S. robusta (Vasey) Heller. Stem 4-10 dm. high, erect, glabrous; leaf- 

 blades firm, dark green, 1-3 dm. long, 4-8 mm. wide, scabrous; panicle dense, 

 usually decidedly lobed; spikelets 2.5-3 mm. long; first glume linear-subulate, 

 about 1.5 mm. long, the second cuneate, about 2 mm. long, firm, very scabrous; 

 lemma about 2 mm. long, obtuse. Eatonia robusta Kydh. River banks: Xeb. — 

 N.M.— Ariz.— Wash. Plain. My-Jl. 



2. S. obtusata (Michx.) Scribn. Stem 3-7 dm. high, erect, glabrous; leaf- 

 blades 3-20 cm. long, 2-5 mm. wide, scabrous; panicle 5-15 cm. long, dense and 

 spike-like, strict; spikelets crowded, 2. .5-3 mm. long; first glume linear-subulate, 

 the second cuneate, 1.5 mm. long and about as broad; lemma 1.5-2 nun. long, 

 obtuse. E. obtusata A. Gray. Prairies, meadows and valleys: IMass. — -Fla. — ■ 

 Ariz. — Mont.; Mex. Plain — Subniont. Ap-Au. 



3. S. intermedia Rydb. Stem 6-8 dm. high, striate, shining; leaf-blades 

 8-15 cm. long, 3-5 nun. wide, usually flat; inflorescence rather narrow and dense; 

 first empty glume about 2 mm. long, subulate, scabrous on the back. E. intcr- 

 mediaWydh. Meadows: Sask. — N.M. — Wash. Plain — Subniont. .Il-S. 



4. S. pallens (Spreng.) Scribn. Stem glabrous, 3-10 dm. liigh; leaf- 

 blades 5-15 cm. long, 2-6 mm. wide, scabrous; panicle 7-20 cm. long, usually 

 nodding, lax; spikelets 3-3.5 mm. long; first emjjty glume subulate, slightly 

 shorter than the second; lemma lanceolate, acute, about 3 mm. long. E. penn- 

 sylvanica A. Gray. Open woods and among bushes: N.B. — Ga. — N.M. — B.C. 

 Plain — Submoni. J(^Au. 



60. MELICA L. Mf.lic-crass. 



Perennials with rootstocks, the stem often bulbous at the base. Panicles in 

 our species narrow, often raceme-like. Si)ikelcts rather few, erect or nodding, 

 l_several-flowered, the lower flowers perfect, sometimes 1 or 2 staiuinate, and 

 the upper neutral. Kmj)ty glumes membranous or hyaline, une(|ual in length. 

 Lemma larger, membranous, the lateral nerves vanishing in the l)road hyaline 

 margins; upper empty lemmas gradually smaller, convolute and enclosing each 

 other, forming an obovate or clavate mass. Palet shorter than the lemma, 

 2-keeled. Styles distinct; stigmas plumose. 



