GRASS FAMILY 63 



Lemma rounded on the back, the margins often ciliate, 2-toothed at the apex, 

 the teeth often awned; awn arising between the teeth, more or less flattened, very 

 often twisted at the base, and frequently geniculate. Palet obtuse or 2-toothed, 

 2-keeled, hyaline. Styles distinct; stigmas plumose. 



Lemma hairy on the back; inflorescence spiJve-liiie, with short, erect branches. 



Empty glumes 15-20 mm. long, long-acuminate. 1. D. Parryi. 



Empty glumes 8-13 mm. long, acute. 



Empty glumes 11-13 mm. long, conspicuously nerved, broad; teeth of the lemma 



subulate, 1-2 mm. long. 2. D. thermalis. 



Empty glumes 8-10 nmi. long, narrow; teeth of the lemma ovate, often only 0.5 

 mm. long. 3. D. spicata. 



Lemma glabrous on the back. 



Empty glumes acute; inflorescence spike-like, with erect branches; stem-leaves erect. 



4. D. interjfiedia. 

 Empty glumes long-acuminate; inflorescence racemiform or spikelet solitary: stem- 

 leaves spreading or ascending. 



Lemma abruptly acuminate; spikelets usually 2-10, on spreading peduncles. 



5. D. californica. 

 Lemma not abruptly acuminate; spikelet usually solitary, if more than one, the 



peduncles erect. 6. D. unispicata. 



1. D. Parryi Scribn. Stem 3-6 dm. high, invested by the marcescent leaf- 

 sheaths at the base; leaf-blades 5-20 cm. long, about 3 mm. wide; spikelets 3-7 

 in the panicle, 5-7 flowered; lemma about 14 mm. long, ovate; awn 12-14 mm. 

 long, flat below, twisted. Mountain valleys: Alta. — N.M. Submonl. — Mont. 

 Je-Au. 



2. D. thermalis Scribn. Stem 3-5 dm. high; sheaths papillate-pilose; lower 

 leaf-blades hairy, the upper glabrous, 5-15 cm. long, involute; spikelets 5-10, 

 5-7-flowered; lemma 5 mm. long, thinly pilose on the back; awn about 7 mm. 

 long. D. spicata pinetorum Piper. Near hot springs and in woods: B.C. — ■ 

 Wash. — Wyo. Submont. — Mont. Jl-Au. 



3. D. spicata (L.) Beauv. Stems 3-7 dm. high, glabrous; leaf-blades scab- 

 rous, 2-15 cm. long, 2 mm. wide, usually involute, often ciliate; panicle 3-5 cm. 

 long; spikelets 5-10, 5-8-flowered; lemma sparingly pubescent with silky hairs; 

 teeth usually about 0.5 mm. long; awn 5-8 mm, long. Woods and hillsides: 

 Newf.— N.C.— N.M.— B.C. Submont.—Mont. My-Jl. 



4. D. intermedia Vasey. Stem 3-5 dm. high; sheaths more or less pubes- 

 cent at least at the mouth; panicle 3-6 cm. long; spikelets 5-10, about 5-flowered, 

 12-15 mm. long; empty glumes acute; lemma 6-8 mm. long, hairy on the mar- 

 gin; teeth about 2 mm. long; awn stout, 6 mm. long. D. Cusicku (Williams) 

 Hitchc. Hillsides and mountains: Que. — N.M. — Calif. — ^IB.C. Mont. — Alp. 

 Jl-Au. 



5. D. californica Bolander. Stems decumbent, 3-10 dm. long, glabrous; 

 leaf-blades 5-20 cm. long, 3-5 mm. wide, flat, with involute tips; spikelets 5-10- 

 flowered; empty glumes lanceolate, purple, glabrous, 15-20 mm. long; lemma 

 glabrous, except the base and the margins, 7 mm. long; awn 7-8 mm. long. Wet 

 meadows: B.C. — -Calif. — Colo. — Mont. Submont. — Mont. My-Au. 



6. D. unispicata Munro. Stems 1-3 dm. high, ascending or erect; sheaths 

 villous with long white hairs, with papillose bases; leaf -blades 5-15 cm. long, 

 2-3 mm. wide, flat, with involute tips; spikelets 4-7-flowered; empty glumes 

 lanceolate, 12-20 mm. long, glabrous; lemma about 8 mm. long; awns 7-8 mm. 

 long. Meadows and hills: B.C. — Calif. — Wis. — Alta. Submont. Je-Au. 



39. SPARTINA Schreb. Marsh-grass. 



Tall perennials, with creeping scaly rootstocks. Spikelets 1-flowered, 

 crowded and imbricate in two rows, in one-sided spikes, the rachis extending 

 beyond the spikelets. Empty glumes 2, firm-membranous, narrow, unequal, 

 keeled. Lemma a little longer and broader than the second empty glume. Palet 

 thin and almost hyaline, obscurely 2-nerved, often exceeding the lemma. Styles 

 elongate; stigmas thread-like, papillose or short-plumose. 



First glume awn-pointed, equalling the lemma; second glume long-awned. 1. S. pectinata 

 First glume acute, shorter than the lemma; second glmne acute. 2. S. gracilis. 



