POACEAE. 23 



3. M. racemosa (Michx.) B.S.P. Stems 3-9 dm. tall, erect, usually much 

 branched: leaf -blades 5-13 cm. long, 2-6 mm. wide, rough: panicle 5-12 cm. 

 long, usually dense and interrupted: spikelets much crowded, the empty scales 

 acuminate, 4-6 mm. long, including the awn, the flowering scale ^-g as long, 

 acuminate, the strongly scabrous midnerve exeurrent as a short point. [M. 

 glomeraia Trin.] — S. Bare, in swamps. — Schists. — Sum. and fall. 



4. M. umbrosa Scribn. Stems 3-9 dm. tall, erect, branched: leaf -blades 5-18 

 cm. long, 2-6 mm. wide, rough: panicle 7-18 cm. long: empty scales of the 

 spikelet 2.5-3 mm. long, awn-pointed, rough, the third scale equalling or some- 

 what exceeding the outer ones, very rough, attenuate into a slender awn 2-4 

 times its length. — S. Eather rare, in moist soil. — Schists. — Sum. and fall. 



5. M. tenuiflora (Willd.) B.S.P. Stems 0-9 dm. tall, erect, slender: leaf- 

 blades 6-lS cm. long, 2-8 mm. wide, rough: panicle 1-2.5 dm. long, slender: 

 empty scales of the spikelet unequal, $-§ the length of the flowering scale, awn- 

 pointed, rough, the flowering one 2.5-3 mm. long, rough, bearing an awn 2-4 

 times its length. [M. Willdenovii Trin.] — M. Bare, in woods and thickets. 

 — • Limestones. — ■ Sum. 



6. M. Schreberi Gmel. Stems 3-9 dm. long, decumbent, diffusely branched: 

 leaf -blades 4-9 cm. long, 1-4 mm. wide, rough: panicle 5-20 cm. long, slender: 

 empty scales of the spikelet minute, the lower one often wanting, the flowering 

 scale, exclusive of the awn, about 2 mm. long, the awn 1-4 mm. long. — S. 

 Rather rare, in dry soil. — Schists. — Sum. and fall. 



7. M. capillaris (Lam.) Trin. Stems erect, wiry, tufted, 5-12 dm. tall: leaf- 

 blades long, often involute when dry, 1-3 mm. wide: panicle 1.5-4 dm. long: 

 spikelets, exclusive of the awn, 3.5-4 mm. long, lanceolate, acuminate, the empty 

 scales usually 4 as long as the spikelet or less, commonly bearing a short awn, 

 the flowering scale bearing an awn longer than its body, sometimes 2 em. long. 

 [M. caespitosa Chapm.] — S. Rather rare, in rocky or sandy soil. — Schists. 

 — Fall. 



19. BRACHYELYTRUM Beauv. Tall perennial grasses, with rather 

 broad flat leaf -blades and a terminal narrow panicle, its branches few, erect and 

 filiform. Spikelets 1-flowered, narrow, the rachilla produced beyond the flower 

 into a long glabrous stipe which sometimes bears a small scale at its apex. 

 Scales 3 (or rarely 4), the 2 outer empty, persistent, very small, the first 

 minute, sometimes almost wanting, the third scale elongate, rather rigid, 

 acuminate into a long erect awn and enclosing a somewhat short dorsally sulcate 

 2-nerved palet of similar texture and a perfect flower, a fourth scale some- 

 times terminating the rachilla-prolongation. Stamens 2. Styles short, distinct. 

 Stigmas elongate, plumose. 



1. B. erectum (Schreb.) Beauv. Stems 3-9 dm. tall: leaf -blades 5-13 cm. 

 long, 6-18 mm. wide, rough: panicle 5-15 cm. long, slender: flowering scale 

 exclusive of the awn, 9-12 mm. long, rough, the awn erect, 2-2.5 cm. long. — 

 Rather common, in woods and on moist banks. — Sum. 



20, HELEOCHLOA Host. Tufted or creeping, perennial grasses, with 

 flat leaf -blades and usually contracted panicles. Spikelets flattened, 1-flowered. 

 Scales 3, awnless, the 2 outer ones unequal, empty, ciliate-keeled, acute, the 

 third scale fully as long as the outer scales, otherwise similar. Stamens 3. 

 Styles distinct. Stigmas plumose. 



1. H. schoenoides (L.) Host. Plant glabrous, the stem and branches pros- 

 trate or nearly so, 1-5 dm, long: leaf -blades 2.5-7.5 cm. long, 2-4 mm. wide: 

 panicle spike-like, 1.5-4 cm. long, partially enclosed in a leaf -sheath: spikelets 



