POACEAE. 37 



Festuca rubra L. Perennial, with short running rootstecks; the whole 

 plant smooth; stems 60-100 cm. tall, slender; leaves narrow, involute, 10-20 

 cm. long; panicle narrow, erect, about 10 cm. long, the short erect branches 

 in twos, spikelet-bearing to the base; spikelets frequently purplish, 10-12 cm. 

 long, 5-6-flowered ; lemma smooth, 5-6 mm. long, tipped with an awn 3-4 mm. 

 long. In moist soil. 



Festuca occidentalis Hook. Densely tufted, the whole plant smooth and 

 bright green; stems 30-60 cm. high; leaf blades smooth, becoming longitudi- 

 nally grooved when dry; panicle narrow, loose, 8-20 cm. long, often drooping 

 at the summit; spikelets green, 3-5-flowered; lemmas scabrous near the apex 

 or smooth, 5-6 mm. long, bearing a slender awn of equal length. In open 

 coniferous woods. 



Festuca viridula Vasey. Densely tufted, dark green, smooth; stems 50- 

 100 cm. high; leaves narrow, erect, soft, 7-nerved, the basal ones involute; 

 panicle loose and open, suberect, 10-15 cm. long; spikelets 3-6-flowered; 

 lemma firm, keeled toward the apex, 5-nerved, acute or sometimes mucronate, 

 smooth or nearly so, 6-7 mm. long. Mt. Carlton, Kreager. Abundant in 

 high mountain meadows. 



Festuca ovina ingrata Hack. Blue Bunchgrass. Densely tufted, the 

 whole plant pale or glaucescent; stems 30-40 cm. tall; leaf blades very nu- 

 merous, setaceous, mostly basal, firm and harshly scabrous; panicle 3-8 cm. 

 long, narrow, one-sided, the branches erect; spikelets 3-5-flowered; lemma 3-5 

 mm. long, tipped by an awn of equal length. Abundant on the prairies. 



Festuca hallii (Vasey) Piper. Densely tufted perennial, 50-100 cm. tall, 

 scabrous throughout; leaf blades very scabrous, strongly involute, breaking 

 away early from the sheaths which remain for several seasons at the base; 

 panicle 7-10 cm. long, narrow, the ascending branches mostly in pairs, spikelet- 

 bearing above the middle; spikelet 8-10 cm. long, 3-5-flowered; lemmas 6-7 

 mm. long, very short awned. Near Steptoe Butte. 



58. PANICULARIA. 



Tall aquatic perennial grasses with terminal panicles; spikelets 

 few-many-flowered, terete, or somewhat flattened; glumes un- 

 equal, obtuse or acute, 1-3-nerved; lemmas membranous, obtuse, 

 rounded on the back, 5-9-nerved, the nerves disappearing in the 

 hyaline apex; palea scarcely shorter than the lemma, rarely 

 longer; grain smooth, enclosed in the lemma and palea, free, 

 or when dry slightly adhering to the latter. 



Spikelets 10-17 mm. long, linear. P. borealis. 

 Spikelets 2-8 mm. long, ovate or oblong. 



Lemma with 5 prominent nerves. P. pauciflora. 

 Lemma with 7 prominent nerves. 



Spikelets 3-4 mm. long. P. nervata. 



Spikelets 4-6 mm. long. P. americana. 



Panicularia borealis Nash. Stems weak, erect, glabrous, 50-100 cm. tall; 

 leaf blades 8-20 cm. long, pale green, nearly smooth; sheaths loose, longer than 

 the intemodes; panicle lax, 15-30 cm. long, the branches single or in twos, 

 usually short and erect; spikelets linear, 10-15 mm. long; lemmas thin, 3.5-4 

 mm. long, 7-nerved, the nerves minutely hispid. Common in shallow ponds. 



