POACEAE 59 



channeled on the inner surface : sessile spikelet about 4 mm. lon^, the first scale somewhat 

 rounded on the back, acute, the awn of the fourth scale 7-10 mm. long, geniculate, tightly 

 spiral at the base, the column exserted ; pedicellate spikelet consisting of a single scale, 

 4-5 mm. long, awnless or awn-pointed, the pedicel linear, not stout, pilose on the outer 

 side near the summit, usually equalling or a little exceeding the internode. [Aiidropor/on 

 tener (Nees) Kunth. ] 



In dry ground. South Carolina to Florida and southern Texas. Also in tropical America. Fall. 



3. Schizachyriuni oligostachyum (Chapm. ) Nash. Smooth and glabrous, some- 

 times glaucous. Stems 9-15 dm. tall, the branches in I's or 2's : leaf-blades 2 dm. long or 

 less, 4 mm. wide or less : racemes single, usually partially included at the base, 6-10 cm. 

 long : sessile spikelet about 6 mm. long, about as long as or a little exceeding the hirsute 

 rachis-internode, the first scale hirsute, the geniculate awn of the fourth scale 10-12 mm. 

 long, closely spiral at the base, the column considerably exserted ; pedicellate spikelet 

 4-5 mm. long, the first scale glabrous, bearing an awn aljout 2 mm. long. lAndropoc/on 

 oligostachyus Chapm.] 



In dry sandy soil, Florida. Fall. 



4. Schizachyrium scoparium (Michx.) Nash. Green or purplish, sometimes 

 glaucous. Stems tufted, 4.5-15 dm. tall, the branches in l's-4's : leaf-sheaths usually 

 glabrous, sometimes more or less hirsute ; blades 5 dm. long or less, 8 mm. wide or less, 

 commonly roughened, and frequently somewhat hirsute above near the base : racemes 

 single, 3-6 cm. long, the hairs on the rachis-internodes and pedicels grayish white : ses- 

 sile spikelet 5-7 mm. long, usually about twice as long as the internode, the first scale 

 generally more or less tuberculate-roughened, the awn of the fourth scale geniculate, 

 8-15 mm. long, closely spiral at the base, the column exserted ; pedicellate spikelet 2-4.5 

 mm. long, the first scale usually glabrous, tipped with an awn generally 1 mm. long or less, 

 the pedicel considerally shorter than the sessile spikelet. l^Andropogon scoparins Michx.] 



In dry sandy soil, New Brunswick to Alberta, Florida and Texas. Summer and Fall. Beoom Grass. 



5. Schizachyrium acuminatum Nash. Stems tufted, 7-10 dm. tall, the branches 

 in l's-3's : leaf-sheaths generally rough toward the summit, compressed, keeled ; blades 

 2 dm. long or less, 5 mm. wide or less, rough : racemes single, finally exserted, 3-6 cm. 

 long, the hairs of the rachis-internodes and pedicels grayish white : sessile spikelet 1 cm. 

 long, about twice the length of the internode, the awn about 1.5 cm. long, geniculate ; 

 pedicellate spikelet consisting of 2 scales, the first 4-5 mm. long, strongly hispidulous and 

 bearing an awn 2 mm. long or less, the pedicel about f as long as the sessile spikelet. 



In dry soil, Mississippi. Fall. 



6. Schizachyrium villosissimum (Kearn.) Nash. Leaf-sheaths, and blades on both 

 surfaces, densely villous. Stems tufted, 8-10 dm. tall, rather stout : leaf-blades 3.5 dm. long 

 or less, 3-5 mm. wide, erect, rather firm : racemes single, about 3 cm. long, exserted from 

 the spathes which are more or less villous : sessile spikelet about 6.5 mm. long, the first 

 scale tuberculate-roughened, acuminate, the awn of the fourth scale usually geniculate and 

 more or less contorted, 10-13 mm. long, tightly spiral at the base, the column exserted ; 

 pedicellate spikelet consisting of a single scale about 2 mm. long with an awn 1-2 mm. 

 long, the pedicel recurved, at least when dry, shorter than the sessile spikelet, pilose above 

 the middle with white hairs, glabrous below. [Andropogon scoparius villosissimus Kearn.] 



In dry sandy soil, Mississippi. Fall. 



7. Schizachyrium maritimum (Chapm.) Nash. Smooth and glabrous, glaucous. 

 Stems 4-6 dm. tall : leaf-sheaths compressed, keeled, the lower ones crowded and over- 

 lapping ; blades 1 dm. long or less, 4 mm. broad or less, widely spreading : racemes 

 single, usually partially included at tlie base, 3-4 cm. long, rather stout, the terminal hairs 

 of the internodes of the rachis 5-7 mm. long : sessile spikelet 8-9 mm. long, about twice 

 as long as the internodes, the awn twisted at the base, geniculate, 9-13 mm. long ; pedicel- 

 late spikelet 5-7 mm. long, awnless, consisting of four scales, the outer two acuminate and 

 usually awn-pointed, the fourth scale enclosing a staminate flower, the iiedicel about ^ as 

 long as the sessile spikelet. [Andropogon maritimus Chapm. ] 



Along the seacoast, western Florida to Mississippi. Fall. 



8. Schizachyrium stoloniferum Nash. Stems 6-10 dm. tall, stoloniferous : leaf- 

 sheaths keeled, more or less hirsute on the margins near the summit ; blades 2 dm. long 

 or less, 2-5 mm. wide, smooth beneath, rough above and hirsute near the base : racemes 

 single, 3-4 cm. long : sessile spikelet 6-7 mm. long, acuminate, about twice as long as the 

 rachis-internode, the first scale strongly tuberculate-roughened, the awn of the fourth scale 

 geniculate, more or less contorted, 8-10 nnu. long, spiral at the base, the cohnnn not ex- 

 serted ; pedicellate spikelet of a single scale about 3 mm. long, hispidulous, bearing an 

 awn shorter than itself. 



In sandy soil, western Florida. Fall. 



