24 



ElG. 13. Andropogon provincialis Lam. (A. furcatus Muhl.) BIG BLUE- 

 STEM.— a, A sessile and pedicellate spikelets; b, first glume of the sessile spike- 

 let; c, second glume of the same; d, third glume; e, fourth or flowering glume, 

 which is awned; /, palea; g, lodicules. Other species of this genus are illustrateds 

 by figures 8-17 in Bui. 7, and 309-323 in Bui. 17. 



13. ANDROPOGON Linn. Sp. PI. 1045. 1753. Spikelets heterogamous, in pairs 

 (or the terminal ternate) at each joint of the articulate and usually hairy 

 rachis, one of each pair (the primary spikelet) sessile, hermaphrodite, and 

 1-flowered, the other pedicellate and either staminate, neutral, or reduced to 

 the pedicel. Glumes of the fertile spikelet 4; the 1st cartilaginous or coriaceous, 

 flattened on the back with a strong nerve near each margin and usually with 

 less prominent nerves between; 2d glume as long as the 1st, but more pointed 

 and keeled; 3d glume empty and usually hyaline; 4th or flowering glume 

 hyaline, awned. Stamens 3. Styles distinct; stigmas plumose. Grain unfur- 

 rowed; free within the hardened outer glumes. Slender or rather coarse per- 

 ennials with solid culms, growing chiefly in dry, sandy, or sterile soils. 



Species about 180, widely distributed over both hemispheres, especially in the 

 tropical and subtropical regions. About forty species in the United States, 

 chiefly in the South and Southwest. 



