9i POACEAE 



base : panicle narrow, 1-2 dm. long, its slender branches erect : spikelets numerous, about 

 2.5 mm. long, lanceolate, often witli 1-3 bristles at the base, glabrous. 

 In pine lands, southern peninsular Florida. Summer and fall. 



36. Panicum stipitatuin Nash. Stems erect, 9-15 dm. tall, much branched : leaf- 

 blades 3 dm. long or more, 4-S mm. wide, acuminate, rough : panicle pyramidal, 1-3 dm. 

 long, its primary branches spreading or ascending : spikelets about 2.5 mm. long, acumi- 

 nate, the fourth scale on a delicate stalk about 0.5 mm. long. 



In moist soil, New Jersey and Pennsylvania to Kentucky, Tennessee and Georgia. Summer 

 and fall. 



37. Panicum rostiatum Muhl. Stems erect, 4-15 dm. tall, branched : leaf-sheaths 



glabrous, or pubescent ; blades 3 dm. long or more, 4-10 mm. wide : panicles 1.5-3 dm. 



long, its branches erect to spreading : spikelets 2.5-3.5 mm. long, lanceolate, acuminate, 



curved at the apex. 



In moist soil, southern New York and New Jersey to Missouri and the Indian Territory, Florida 

 and Texas. Summer and fall. 



38. Panicum linearifolium Scribn. Stems tufted, slender, erect, glabrous, simple, 

 1.5-4 dm. tall : leaf-sheaths glabrous or hirsute ; blades glabrous or pubescent, elongated, 

 7-25 cm. long, 2-4 mm. wide, the upjiermost blade the longest and often extending beyond 

 the panicle : primary panicle loose and open, 4-10 cm. long, its branches ascending : spike- 

 lets 2-2.5 mm. long, obtuse or acutish, pubescent with spreading hairs. 



In dry soil, especially on hillsides, New York and New Jersey to Missouri and the Indian Terri- 

 tory. Summer and fall. 



39. Panicum perldngum Nash. A tufted puliescent perennial. Stems 2-4 dm. 



tall, simple, glabrous, or siiaringly pubescent, the nodes barbed, finally with short basal 



stems : leaves 1 or 2 ; sheaths hirsute with long ascending hairs ; blades elongated, linear, 



erect, papillose-hispid beneath, 2-3 mm. wide, the upper blade commonly '8-14 cm. long : 



panicle much exserted, generally extending beyond the apex of the upper leaf-blade, 4-6 



cm. long, its branches erect or erect-ascending : spikelets about 3.25 mm. long and 1.5-1.75 



mm. wide, pubescent with a few scattered long hairs. 



On prairies and in dry soil, Illinois to South Dakota and the Indian Territory. Spring and sum- 

 mer. 



40. Panicum depauperatum Muhl. Stems erect, 3 dm. tall or less, simple : leaf- 

 sheaths glabrous to hirsute ; blades 8-15 cm. long, elongated, 1-4 mm. wide, the upper one 

 sometimes much exceeding the panicle : primary panicle much exserted, 2-8 cm. long, 

 usually linear, its branches erect or nearly so : spikelets 3-4 mm. long, glabrous, acute. 



In dry places, Maine to Minnesota, Florida and Texas. Summer and fall. 



41. Panicum glabrifolium Nash. Glabrous and shining. Stems tufted, 1.5-4 dm. tall, 

 erect, rigid, slender, leafy, finally much branched : leaf-sheaths with a tuft of liairs on each 

 margin at the apex ; blades narrowly linear, erect, rigid, thickish, long-acuminate, nar- 

 rowed toward the base, those on the shoots 1.5 dm. long or less, 3-4 mm. wide, those on 

 the flowering stems 3-9 cm. long, 1-3 mm. wide : panicle ovate, 4 6 cm. long, its branches 

 spreading or somewhat ascending : spikelets 1.3-1.5 mm. long and 0.7 mm. wide, obovoid. 



In low pine lands, Florida. Summer. 



42. Panicum strigosum Muhl. A tufted densely papillose-hirsute perennial, the 

 pubescence spreading. Stems 2-4 dm. tall, simple : leaves 2 or 3 ; sheaths much shorter 

 than the internodes ; blades erect, lanceolate, 2-7 cm. long, 3-10 mm. wide : panicle much 

 exserted, 5-8 cm. long, broadly ovate, its branches spreading or somewhat ascending : 

 spikelets 1.3-1.5 ram. long and about 0.8 mm. wide, oval, glabrous. 



In dry or moist pine lands. North Carolina and Tennessee to Florida. Spring and summer. 



43. Panicum polycaulon Nash. Yellowish green. Stems tufted, naked above, 2 

 dm. tall or less, erect, simple, finally branched : leaf-sheaths ciliate on the margin ; blades 

 erect or ascending, narrowly oblong-lanceolate, 2-7 cm. long, 2-8 mm. wide, ciliate on the 

 margin : panicle broadly ovate, 3 cm. long or less, its branches spreading or ascending, the 

 main axis and generally the branches sparingly pilose : sjiikelets about 1.5 mm. long and 

 0.8 mm. wide, obovoid, obtuse, glabrous. 



In low pine lands, Florida to Mississippi. Also in Cuba. Summer. 



44. Panicum ciliatum Ell. Stems tufted, 1-2.5 dm. tall, simple, glabrous, the axis 

 of tlie panicle and its branches hirsute : leaves usually 2 ; sheaths shorter than the inter- 

 nodes ; blades spreading or ascending, glabrous on both surfaces, conspicuously ciliate on 

 the margins, acute at the apex, somewhat cordate at the ba.se, narrowly elliptic, linear or 

 lanceolate, usually 2-6 cm. long and 5-10 mm. wide, rarely larger : panicle 3-5 cm. long, 

 broadly ovate, its branches ascending : spikelets 1.8-2 mm. long and about 1 mm. wide, 

 elliptic, pubescent with short spreading hairs, rarely nearly glabrous, the first scale about 

 •2 as long as the spikelet. 



In sandy soil, North Carolina to Florida and Mississippi. Spring and summer. 



