GRAMINEAE (GRASS FAMILY) 93 



long ; palea minute, nerveless. Tall and stout reed-like perennials, with elon- 

 gated flat leaves, racemes crowded in a panicle and clothed with long silky hairs, 

 especially in a tuft around the base of each spikelet (whence the name, from 

 fpiov, wool, and &v6os, flower). 



* Awn terete, straight. 

 ^ Hairs at base of spikelets copious, as long as the glumes or longer ; panicle-axis 



and upper part of culm densely appressed-villous. 

 M- Panicle loose and open; hairs longer than the glumes. 



1. E. saccharoides Michx. Culm 1-2 m. high, usually with a dense ring of 

 appressed hairs at the nodes ; leaves 1-2.5 cm. wide, villous ; panicle tawny or 

 purple. Moist ground, N. J. and southw., rare. 



Sept., Oct. FIG. 49. 



W--W- Panicle dense and compact ; hairs about as long 

 as the glumes. 



2. E. compactus Nash. Culm 1-3 m. high, villous 

 at the nodes; blades 6-12 mm. wide, usually villous 

 only on the upper surface near the base ; panicle 

 tawny. Moist ground, N. J. and southw. Aug., 

 Sept. 



H- -- Hairs at base of spikelets rather sparse or want- 

 ing, shorter than the glumes; culm and axis of 49 E. saccharoides x IV 

 panicle glabrous or sparsely villous. 



3. E. brevibarbis Michx. Culm 1-2 m. high, sparingly villous at the nodes ; 

 sheaths glabrous ; blades 6-10 mm. wide, scabrous ; panicle purple, narrow, the 

 branches appressed, sparingly silky, appearing striate from the stiff straight 

 awns. Moist ground, Del. and southw. Sept., Oct. 



* * Awn flattened and twisted. 

 - Panicle pale, axis very villous; basal hairs copious, exceeding the glumes. 



4. E. divaricatus (L.) Hitchc. Culm 1.5-3 m. high, nodes and upper portion 

 appressed-villous ; sheaths glabrous ; leaves 1.5-2.5 cm. wide ; panicle loose, silky. 

 (E. alopecuroides Ell.) Moist ground, N. J. to Ga., w. to Ky. and s. Mo. Sept. 

 *-- Pa nicle dark, axis sparsely villous; basal hairs rather sparse, scarcely 



as long as the glumes. 



5. E. contdrtus Baldw. Culm 1-2 m. high, nodes soon glabrous ; sheaths 

 glabrous ; leaves 5-15 mm. wide ; panicle narrow, less silky than in the preceding. 

 Low meadows, Va. to Ky., and southw. 



4. ANDROP6GON [Royen] L. BEARD GRASS 



Spikelets in pairs (one sessile and perfect, the other pediceled, sterile, often 

 rudimentary) at each joint of the articulate rhachis ; glumes of fertile spikelet 

 subequal, indurated, the first dorsally flattened, with a strong nerve near each 

 margin, the midnerve faint ; second glume keeled above ; first lemma empty, 

 hyaline ; fertile lemma membranaceous or hyaline, awned ; palea hyaline, 

 sometimes obsolete. Tall tufted perennials; spikes lateral and terminal, the 

 rhachis and usually the pedicels long-villous with silky hairs (whence the name, 

 composed of avyp, man, and ir&ywv, beard.) 



Racemes solitary ; joints of the rhachis clavate 1. A. scoparius. 



Racemes in fascicles of 2-6 ; joints of the rhachis not clavate. 

 Pedicellate spikelet reduced to the pedicel or the glumes only ; racemes 

 usually subtended by a foliaceous spathe (the upper sheath) ; rhachis- 

 joints very slender. 



Racemes not Jonger than the spathe, which incloses the common peduncle. 

 Branches of inflorescence in a dense terminal corymbiform cluster . 2. A. glomeratut. 

 Branches of inflorescence scattered along the culms .... 8. A. virginicus. 

 Racemes, or some of them, on peduncles exserted beyond the spathes. 



Upper sheaths inflated ; racemes delicate, flexuous 4. A. Elliottii. 



Upper sheaths not inflated ; racemes stouter, strict 5. A. ternarius 



Pedicellate spikelet staminate, with glumes and lemmas . . . . 6. A. 



