POACEAE 83 



most one, densely papillose-hirsute with spreading hair.s ; bhides 2-12 cm. long, 2-7 mm. 

 wide, papillose-hirsute on both surfaces : axis of the inflorescence 4 cm. long or less ; 

 racemes 4-13, 4-13 cm. long, finally widely spreading, usually in a whorl at the base and 

 the remainder alternate or approximately in pairs : spikelets about 2.5 mm. long, about 

 0.5 mm. wide, lanceolate, acuminate, in pairs, occasionally with a delicate basal bristle ; 

 first scale minute, glabrous, the second and third scales appressed-pubescent, the second 

 3-nerved, about A as long as the spikelet, the third 7-nerved, noticeably longer tiian the 

 fourth one which is slightly less than 2 mm. long, elliptic, greenisli when mature. 

 In dry sandy soil, Florida. Also in the West Indies and South America. Summer. 



10. Syntherisma sanguinale (L. ) Dulac. Stems 1 m. long or less, finally branched, 

 prostrate at the base and rooting at the lower nodes : lower leaf-slieaths densely papillose- 

 hirsute ; blades 4-20 cm. long, 4-10 mm. wide, more or less papillose-hirsute on both sur- 

 faces : axis of the inflorescence 1 cm. long or less ; racemes 3-10, 5-18 cm. long, usually 

 erect or ascending, commonly digitate : spikelets 2.5-3 mm. long, about 0.8 mm. wide, 

 elliptic-lanceolate, acute, in pairs ; first scale small, glabrous, tlie second and tliird appressed- 

 pubescent, the second about I as long as the spikelet, ovate-lanceolate, 3-nerved, the third 

 about as long as the flowering one, 7-nerved, the first and second nerves on each side hispid 

 above the middle, fourth scale yellowish M-liite when mature, acutely apiculate, elliptic- 

 lanceolate. [Panicum sanguinale L.] 



In cultivated places, nearly throughout North America. Introduced. Spring to fall. 



11. Syntherisma fimbriktum (Link) Nash. Stems 8 dm. long or less, finally 

 branched, prostrate at the base and rooting at tlie lower nodes : lower leaf -sheaths densely 

 papillose-hirsute with spreading hairs ; blades 2-8 cm. long, 5-10 mm. wide, erect or 

 ascending, both surfaces glabrous or more or less pubescent : axis of the inflorescence 2 cm. 

 or less long ; racemes 2-9, 2-12 cm. long, erect or ascending, alternate, in pairs or whorls : 

 spikelets 3-3.5 mm. long, about 0.8 mm. wide, lanceolate, very acute, in pairs ; first scale 

 small, glabrous, the second and third appressed-pubescent with long hairs, the second one 

 I to -4 as long as the spikelet, lanceolate-cuneate, 3-nerved, tlie third sliglitly exceeding the 

 flowering scale, 7-nerved, the pubescence usually becoming widely spreading, the fourth 

 one lanceolate, very acute, yellowish white at maturity. 



In dry sandy soil. District of Columbia to Florida and Texas. Introduced. Summer. 



12. Syntherisma barbatum (Willd. ) Nash. Stems 5 dm. long or less, brandling, 

 often rooting at the lower nodes : leaf-sheaths glabrous ; blades lanceolate, 3 cm. long or 

 less, 3-5 mm. wide, glabrous on both surfaces, sparsely ciliate at the base : racemes in 

 pairs, 4-6 cm. long, erect or ascending : spikelets 3.5-4 mm. long, slightly exceeding 1 

 mm. wide, lanceolate, acute, in pairs ; first scale small, glabrous, the second and third 

 appressed-pubescent with very long hairs, the second one about i as long as the spikelet, 

 lanceolate-cuneate, 3-nerved, the third 7-iierved and in the long-pedicelled spikelet the 

 pubescence of two kinds ; fourth scale yellowish white at maturity, elliptic-lanceolate, 

 acuminate. 



In sandy soil. Mississippi. Introduced. Summer. 



28. TRICHACHNE Nees. 



Perennial grasses, with flat leaf-blades, usually tufted stems and narrow or contracted 



panicles, usually densely hairy. Spikelets numerous, articulated below the empty scales, 



1-flowered, lanceolate, acute or acuminate. Scales 4, the outer 3 membranous, empty, the 



second and usually also the much shorter first densely silky-pilose or long-ciliate on the 



margins, often acuminate, and sometimes with a short bristle at the apex, the fourth scale 



shorter, chartaceous, glabrous and shining, finally indurated, enclosing a shorter palet of 



similar texture and a perfect flower. Stamens 3. Styles distinct. Stigmas plumose. 



Panicle tawny white : spikelets 4-.5 mm. long, lanceolate. 1. T. insulare. 



Panicle silvery white : spikelets about 3 mm. long, ovate-lanceolate. 2. T. mccharatiim. 



1. Trichachne insulare (L. ) Nash. Stems 1-1.5 dm. tall, stout, finally more or less 



branched : leaf-sheaths usually glabrous, or sometimes papillose-hirsute ; blades ascending, 



sometimes drooping, 1-3 dm. long, generally 5-20 mm. wide : panicle tawny white, usually 



2-3 dm. long, 1-2 cm. wide : spikelets 4-5 mm. long, long-acuminate, the hairs less copious 



than in the following species. l_Panicum leucophaeum H.B.K.] 



In cultivated ground, on banks, and in coral soil, Florida and southern Texas. Also in tropical 

 countries. Spring to fall. 



2. Trichachne sacchar^tum (Buckl.) Nash. Stems 4-8 dm. tall, finally somewhat 

 branched : leaf-sheaths glabrous, or sometimes paiiillose-hirsute ; blades erect or ascending, 

 generally less than 1.5 dm. long and usually less than 5 mm. wide : panicles silvery white, 



