POACEAE 151 



flowers. Scales 5-7, the 2 lower empty, the first narrow, acute, the second longer and 

 broader, keeled, acuminate or mucronate, the flowering scales broader, rounded on the 

 back, acuminate or mucronate, at length coriaceous and shining, the remaining scales 

 empty, gradually narrower, involving each other ; palet thin, 2-keeled. Stamens 2, or rarely 

 solitary in each flower. Styles short, distinct. Stigmas plumose. 



1. Korycarpus diandrus (Michx.) Kuntze. Stems 4-12 dm. tall, erect, rough be- 

 low the panicle : leaf -sheaths overlapping, confined to the lower part of the stem, some- 

 times pubescent ; blades 2-6 dm. long, 1-2 cm. wide, commonly rough : panicle, often 

 reduced to a raceme, 5-20 cm. long, its branches erect : spikelets 12-16 mm. long, 3-5- 

 flowered, the flow r ering scales abruptly acuminate. [Diarrhena Americana Beauv.] 



In rich woods, Ohio to Kansas, Georgia, Tennessee and the Indian Territory. Summer and fall. 



108. UNIOLA L. 



Usually tall perennial grasses, with flat or convolute leaf -blades and contracted or open 

 panicles, the branches sometimes nodding. Spikelets many, erect, or sometimes nodding, 

 laterally compressed, 2-edged, 3-many-flowered, the flowers perfect or the upper ones 

 staminate. Scales 6-many, compressed-keeled, sometimes winged, the lower 3-6 empty, 

 gradually enlarging, the flowering scales many-nerved, similar to the upper ones of the 

 lower empty scales but larger, the remaining scales, if any, empty ; palet somewhat rigid, 

 2-keeled, the keels narrowly winged. Stamens 1-3. Styles distinct. Stigmas plumose. 



Stamen 1 : not strand grasses. 



Inflorescence long and very slender, usually nodding at the apex. 



Leaf-sheaths glabrous. 1. U. laxa. 



Leaf-sheaths, at least the lower ones, strongly hirsute. 2. U. longtfolia. 



Inflorescence not long and slender. 



Spikelets less than 2 cm. long, the scales less than 10. 



Small empty scales at the base of the spikelet 3 : flowering scales ascend- 

 ing, longer than the acute palet : inflorescence usually with long 

 spreading branches. 3. U. nitida. 



Small empty scales at the 'base of the spikelet 4 or 5 : flowering scales 

 widely spreading, equalled or exceeded by the long-acuminate 

 palet : inflorescence with short branches. 4. U. ornithoryncha. 



Spikelets 2.5-4 cm. long, oval to ovate, the scales 10-20. 5. U. latifolia. 



Stamens 3 : strand grass. 6. U. paniculata. 



1. Unlola laxa (L.) B.S.P. Stems 4-12 dm. tall, erect, slender: leaf -blades 1-4 

 dm. long, 2-6 mm. wide, usually erect, each attenuate into a long tip : panicle slender, 

 1-3 dm. long, erect, strict, or nodding at the summit, its branches erect : spikelets about 

 6 mm. long, 3-6-flowered, the flowering scales 4-5 mm. long, acuminate, spreading in 

 fruit. [ U. gracilis Michx. ] 



In sandy soil, Long Island to Pennsylvania, Kentucky, Florida and Texas. Summer and fall. 



2. Uniola longifolia Scribn. Stems tufted, 8-12 dm. tall : leaf-sheaths, at least the 

 lower ones, densely hirsute ; blades flat, 3 dm. long or less, narrowed at both ends, 6-12 

 mm. wide : panicle 2-4.5 dm. long, its branches short and appressed, or the lower ones 

 sometimes long and ascending : spikelets 3-4-flowered, usually about 6 mm. long, the flow- 

 ering scales about 5 mm. long. 



In dry usually sandy soil, Tennessee to Florida and Louisiana. Summer and fall. 



3. Uniola nitida Baldw. Stems 6-15 dm. tall : leaf -blades 2 dm. long or less, 4-8 

 mm. wide: panicle 1-1.5 dm. long, its branches spreading or ascending, the larger ones 

 4-6 cm. long, or sometimes reduced to a raceme : spikelets 1-1.5 cm. long. 



In low woods, Georgia and Florida to Louisiana. Spring and summer. 



4. Uniola ornithorhyncha Nees. Stems 2.5-6 dm. tall, slender: leaf -blades flat, 

 6-12 cm. long, 4-7 mm. wide : panicle 4-8 cm. long, its branches short and ascending, 

 sometimes bearing but a single spikelet : spikelets crowded, 8-10 mm. long, broader than 

 long, the flowering scales long-acuminate. 



In low woods, Mississippi and Louisiana. Summer and fall. 



5. Uniola latifolia Michx. Stems 6-15 dm. tall, erect : leaf-blades 1-2.5 dm. long, 

 6-25 mm. wide, flat, the base often ciliate : panicle lax, 1.5-2.5 dm. long, its long branches 

 filiform and pendulous : spikelets many-flowered, oval to ovate, much flattened, 2.5-4 cm. 

 long, on long capillary pendulous pedicels, the flowering scales 9-12 mm. long, ciliate- 

 hispid on the winged keel. 



In moist places, Pennsylvania to Illinois, Kansas, Florida and Texas. Summer and fall. 



6. Uniola paniculata L. Stems 1-2.5 m. tall, erect : leaf-blades 3 dm. long or 

 more, about 6 mm. wide, involute, at least when dry, attenuate into long slender tips : 

 panicle 2-3 dm. long or more, its branches erect or ascending, strict, rigid : spikelets 



