152 



GRAMINEAE (GRASS FAMILY) 



154. M. mutica. 



Spikelet displayed 



x2. 



1. EUMEXICA Scribn. Glumes broad and papery ; sterile lemmas broad and 

 truncate, convolute around each other ; lemmas awnless. 



* Glumes subequal, nearly as long as the 2-flowered spikelets. 



1. M. mutica Walt. Culms erect from knotted rootstocks, wiry, 6-9 dm. high ; 

 sheaths usually overlapping, scabrous ; lower blades short, the upper 10-20 cm. 



long, 2-10 mm. wide; panicle 0.8-2.5 dm. long, simple, with 

 filiform ascending branches or reduced to a raceme ; spikelets 

 7-10 mm. long, pendulous on short pedicels, florets spreading, 

 6-8 mm. long; lemmas scabrous, obtuse, the intermediate nerves 

 vanishing above ; empty lemmas cucullate above, exceeded by 

 the fertile ones. Dry rocky open woods and thickets, Fa. to 

 Fla., w. to Wis., la., and Tex. Apr., May. FIG. 154. From 

 Va. southw. occasional specimens have sparsely pubescent 

 sheaths and the blades somewhat pubescent on the lower sur- 

 face. (3/. diffusa Pursh ; M. mutica, var. diffusa Gray) ; not 

 varietally distinct. 



* * Glumes unequal, shorter than the 3-5-flowered spikelets. 



2. M. nitens Nutt. Culms 8-12 dm. high, erect from a short horizontal 

 rootstock ; sheaths overlapping, glabrous; blades 1-2 dm. long, 4-8 mm. wide; 

 panicle 1.5-2.5 dm. long, the slender spreading branches solitary or in pairs, 

 simple or sparingly branched ; spikelets numerous, 10-12 mm. long, usually 

 3-flowered, pendulous on short pedicels; lemmas 7-9 mm. long, scabrous, acute; 

 empty lemmas broad at the summit, exceeded by the fertile ones. (M. diffusa 

 of recent authors, not Pursh.) Rocky woods, Pa. to Neb., and southw. May, 

 June. 



3. M. PortSri Scribn. Culms erect, slender, 5-7.5 dm. high; sheaths over- 

 lapping, scabrous; blades 12-23 cm. long, 2-6 mm. wide, scabrous; panicle 

 1.5-2.5 dm. long; the narrow spikelets pendulous and racemose along the 

 slender ascending branches, 4t--flowered, 10-13 mm. long ; lemmas 7-8 mm. 

 long, subacute, scabrous ; empty lemmas like the fertile ones and exceeding 

 them. (M. parviftora Scribn.) Bluffs and stony hillsides, la. to Mo., and 

 westw. 



2. BROMELICA Thurb. Glumes narrow, scarious-margined ; sterile lem- 

 mas similar to the fertile which are awned below the bidentate apex; spike- 

 lets 5-9-flowered. 



4. M. Smfthii (Porter) Vasey. Culms 

 erect, slender, 7-12 dm. high ; sheaths sca- 

 brous ; blades 10-20 cm. long, 6-12 mm. 

 wide, lax, scabrous ; panicle 1.2-2.5 dm. 

 long, the solitary remote spreading branches 

 spikelet-bearing toward the ends ; spikelets 

 3-6-flowered, 18-20 mm. long, more or less 

 tinged with purplish chestnut ; glumes acute ; 

 lemmas glabrous, about 10 mm. long, ex- 

 cluding the awn, which is \-% as long. (Avena Porter.) 

 Moist woodlands, n. Mich, and westw. May-July. FIG. 

 155. 



5. M. striata (Michx.) Hitchc. Similar to the preceding, 

 usually not so tall and more slender ; leaves narrower ; sheaths 

 closed to the summit, the ligule sheathing the culm ; panicle- 

 branches ascending or spreading at the ends ; spikelets 2.2- 

 2.5 cm. long ; glumes broader, conspicuously colored as are 



156. M. striata xi. often the florets which are short-bearded at the base; awn 



Spikelet with glumes s long as the lemma or longer. (Avena Michx.) Rocky 



separated. wooded lands, e. Que. to Pa., Minn., and westw. FIG. 



Floret. 156, 



155. M. Smithii. 

 Spikelet displayed 



