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 

 tpiov, wool, and 4v0o*, flower). 



* Awn terete, straight. 

 t- Hairs at base ofspikelftx copious, as long as the glumes or longer ; panicle-axis 



and upper part of culm densely appressed-villuux. 

 *+ 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. 



*+- 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. 



t- +- Hairs at base of spikelets rather sparse or want- 



ing, shorter than the glumes; culm and axis of 49 E saccharoides x i^ 

 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. 

 t- 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 1.5-2.6 cm. wide ; panicle loose, silky. 

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

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



as long as the glumes. 



5. E. cont6rtus 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. ANDROPdGON [Royen] L. BEARD GRABS 



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 lateraf and terminal, the 

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

 composed of dv-f/p, man, and vuyuv, beard.} 



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



Racemes in fascicle's of 2-fi ; 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 'onper than the spathe, which incloses the common peduncle. 

 Branches of inflorescence in a dense terminal coryinblfonn cluster . 2. A. glomeratu*. 

 Branches of inflorescence scattered along the culms .... 8. A. virginicw*. 



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



I'pper sheaths inflated ; racemes delicate, flexuous ..... 4. A. Ellivttii. 



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



Pedicellate spikelet stauiinate, with glumes and lemmas . . . . 6. A. furcatM. 



