GRAMIXF.JE. (GRASS FAMILY.) 583 



64. ANDROPOGON, L. BEARD-GRASS. 



Spikclets in pairs upon each joint of the slender rhachis, spiked or raccmed ; 

 one of them pcdicelled and sterile, often a mere vestige : the other sessile, with 

 the lower flower neutral and of a single palea ; the upper perfect and fertile, of 

 2 thin and hyaline palese shorter than the herbaceous or chartaceous glumes, the 

 lower awned from the tip. Stamens 1 -3. Grain free. Coarse and mostly 

 rigid perennial Grasses, with lateral or terminal spikes commonly clustered or 

 digitate ; the rhachis hairy or plumose-beai'ded, and often the sterile or stami- 

 nate flowers also (whence the name, composed of dvfjp, av&pos, man, and Trcoya)?, 

 beard). 



# Ststrile spikelet staminate (stamens 3), awnless: spikes digitate. 



1. A. f lire situs, Muhl. Culms (4 high) and leaves nearly smooth, 

 bearing 3-5 straight and rather rigid hairy spikes together at the naked summit 

 (or fewer on lateral branches) ; spikelets approximated, rouglush-downy ; awn 

 bent. Sterile soil ; common, Sept. 



* * Sterile spikelet neutral, reduced to a small pointed glume raised on a long bearded 

 pedicel ; the fertile 2 - 3-androus, bearing a slender mostly bent or twisted awn : culms 

 paniculate-branched. 



2. A. sco parius, Michx. Culms slender (2 - 4 high), with many pa- 

 niculate branches ; the lower sheaths and the narrow leaves hairy ; spikes mostly 

 tingle, terminating the short branches, peduncled, very loose, slender (2' long, often 

 purple), sparsely silky with dull white hairs; the zigzag rhachis hairy along the 

 edges ; pairs of spikelets rather distant. Sterile or open sandy soil ; common. 

 July - Sept. 



3. A. argcnteilS, Ell. Culms rather slender (about 3 high) ; spikes in 

 pairs, on a peduncle exceeding the sheaths, dense, very silky with long white hairs 

 (l'-2 ; long) ; rudimentary flower much shorter than the hairs of its pedicel. 

 Sterile soil, Virginia, Illinois? and southward. Sept., Oct. Spikes much 

 denser, and the flowers larger and more silky, than in the next ; which it con- 

 siderably resembles. 



* * * Sterile spikelet abortive, reduced to a mere aum-like plumose pedicel, or bearing 

 distinct rudiment of a Jlower ; the fertile \-androus, and bearing a straight slender 

 awn : spikes clustered, lateral and terminal, partly enclosed in the flattened bract" 

 like sheatlis ; the slender rhachis, $*c. clothed ivith copioui very long and silky 

 (white) hairs. 



4. A. VirglltlCUS, L. Culm flattish below, slender, sparingly short- 

 branched above (3 high) ; sheaths smooth ; spikes 2 or 3 together in distant oppressed 

 clusters, weak and soft (!' long). Sandy soil ; Massachusetts to Illinois, and 

 southward. Sept. 



5. A. msicroftrilS, Michx. Culm stout (W- 3 high), bushy-branched ax 

 the summit, loaded with numerous spikes forming dense leafy clusters; sheaths 

 rough, the upper hairy. Low grounds, New York to Virginia, near the coast, 

 and southward. Sept., Oct. 



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