MANUAL OF THE GRASSES OF THE UNITED STATES 



755 



blades 3 to 6 mm. wide, flat; raceme 

 3 to 6 cm. long, mostly curved, the 

 filiform peduncles mostly wholly or 

 partly included in the sheaths, com- 

 monly spreading, the rachis slender, 

 flexuous, pilose, sometimes copiously 

 so; sessile spikelet mostly 6 to 8 mm. 

 long, scabrous, the awn 8 to 15 mm. 

 long; pedicellate spikelet usually re- 

 duced, short-awned, spreading, the 

 pedicel pilose. % — Prairies, open 

 woods, dry hills, and fields, Quebec 

 and Maine to Alberta and Idaho, 

 south to Florida and Arizona. A form 

 with villous foliage has been segre- 

 gated as A. scoparius var. villosissimus 

 Kearney (Schizachyrium villosissimum 

 Nash) . Schizachyrium acuminatum 

 Nash was described from a specimen, 

 otherwise typical, having spikelets 

 10 mm. long. Specimens with spike- 

 lets 4.5 to 6 mm. long and reduced 

 sterile spikelets have been differen- 

 tiated as var. frequens Hubb., and 

 northern specimens with few racemes, 

 relatively distant spikelets 7 to 8 

 mm. long, and sterile spikelets, in- 

 cluding awn, 6.5 to 10 mm. long, as 

 var. septentrionalis Fern, and Grisc. 

 Specimens from Virginia to South 

 Carolina, collected from June 8 to 

 September 13, have been segregated 

 as Andropogon praematurus Fernald. 15 



Andropogon scoparius var. neo- 

 mexicanus (Nash) Hitchc. (Fig. 1147.) 

 Rachis and pedicels copiously villous, 

 the rachis mostly nearly straight. In 

 the Southwest the species verges into 

 this variety. % (Schizachyrium 

 neomexicanum Nash.) — Sandy soil 

 and rocky hills, Texas to Arizona. 



9. Andropogon littora is Nash. (Fig. 

 1148.) Resembling A. scoparius, but 

 culms more compressed, with broad, 

 keeled, overlapping lower sheaths, 

 often bluish-glaucous, the flat tufts 

 crowded on a slender rhizome, de- 

 cumbent or bent at base; blades 4 



15 There are numerous collections of A. scoparius 

 throughout its range made in June, July, and August. 

 A. praematurus, with a single pedicellate spikelet at 

 each joint of the rachis, was differentiated from A. 

 scoparius, which is said to have 2 pedicels. In A. sco- 

 parius, as in all species of Andropogon, each rachis 

 joint bears 1 sessile and 1 pedicellate spikelet. The 

 second "truncate" pedicel described was undoubtedly 

 a rachis joint from which a sessile spikelet had fallen. 



Figure 1147. — Andropogon scoparius var. neomexi- 

 canus, X 1 (Wooton, N. Mex.) 



to 6 mm. wide; rachis joints and 

 pedicels copiously long-villous. % 

 — Sandy shores, Ontario; Massachu- 

 setts and Staten Island, N. Y., to 

 North Carolina; Ohio (Sandusky); 

 Indiana (sand dunes of Lake Michi- 

 gan); southeastern Texas. A short 

 specimen without rhizomes and with 

 a rather crowded inflorescence, from 

 Elizabeth Islands, Mass., has been 

 described as A. scoparius var. ducis 

 Fern, and Grisc. 



10. Andropogon divergens (Hack.) 

 Anderss. ex Hitchc. (Fig. 1149.) 

 Culms rather robust, 80 to 120 cm. 

 tall, sparingly branching toward the 

 summit; sheaths grayish villous, the 

 lower crowded, compressed-keeled; 

 blades rather firm, 3 to 6 mm. wide, 

 villous, elongate, flat or folded; ra- 

 ceme mostly 3 to 4 cm. long, mostly 

 6- to 8-jointed, rather stout, usually 

 partly included, the rachis slightly to 

 strongly flexuous, rather stout, the 

 joints long-ciliate on the upper half, 

 rarely throughout, and with a short 

 tuft of hairs at the summit, the 

 pedicel long-ciliate on the upper half; 

 sessile spikelet 6 to 8 mm. long, mi- 

 nutely roughened, the awn 5 to 10 

 mm. long; pedicellate spikelet about 

 as long as the sessile one, the first 



