GEAMINE^. (grass FAMILY.) 583 



64. AIVDROPOOON, L. Beabd-Geass. 



Spikelete in pairs upon each joint of tl\e slender rhachia, spiked or racemed; 

 one of tliem pedicelled 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 palo» 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-bearded, and often the sterile or stami- 

 nate flowers also (whence the name, composed of dvijp, avSpoc, man, and irayav, 

 beard). 



* Sterile spikelet staminate (stamens 3), aimless : spikes digitate, 



1. A. furc&tus, Muhl. Oulms (4° high) and leaves nearly smooth, 

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

 (or fewer on lateral branches) ; spikelets ^proximated, roughish-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 lender mostly bent or twisted awn : cidms 

 paniculate-branched. 



2. A. scoparins, Michx. Culms slender (2° -4° high), with many par 

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

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

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

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

 July - Sept. 



3. A* argenteus, Ell. Culms rather slender (about 3° high) ; spikes in 

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

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

 Sterile soil, Virginia, Illinois 1 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 awn-like plumose pedicel, bearing no 

 distinct rudiment of a flower; the fertile l-androus, and bearing a straight slender 

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

 like sheaths; the slender rhachis, ^c. clothed with copious very long and silky 

 {white) hairs. 



4. X. Til'ginicus, L. Culm flattish below, slender, sparingly short- 

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

 clusters, weak and soft (1' long). — Sandy soil ; New York to Illinois, and south- 

 ward. Sept. 



5. A. macroftrus, Michx. Culm stout (2°-3° high), Jusiy-ironc/iaiot 

 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. 



