POACEAE. 13 



dm. long, composed of appressed one-sided racemes, the lower ones 3-5 cm. 

 long: spikelets nearly sessile^ 2 mm. long, singly disposed, broadly obovoid, 

 glabrous. — Hammocks, pinelands and cultivated grounds, U. keys, L. keys. — • 

 (Ber., Bah.) 



3 J- 5, P. amarulum Hitchc. & Chase. Glabrous, glaucous: stems 8-12 dm. tall: 

 leaf -sheaths overlapping; blades generally 3-6 dm. long, 8-16 mm. wide, long- 

 acuminate, thick, involute, at least toward the apex: panicle large, but narrow, 

 3-7 dm. long: spikelets 4-5 mm. long, usually rather narrow, the first scale 

 about 2 as long as the spikelet. — Shores and coastal sand-dunes, U. S. keys, 

 U. keys.— [E. K.]—(Bah.) 



3^6. P. virgatum L. Glabrous: stems erect, 9-15 dm. tall: leaf-blades elongate, 

 3 dm. long or more, 6-12 mm. wide, flat, glabrous or pubescent: panicle 1.5-5 

 dm. long, its branches widely spreading or sometimes nearly erect: spikelets 

 ovate, acuminate, 4-4.5 mm. long, glabrous. — Hammocks, U. keys, L. keys. — 

 [E. K.]—{Ber., Cuha.) 



U:7. P. maximum Jacq. Stems 1-2 m. tall or more, leafy: leaf -sheaths glabrous 

 or tubereulate-pubescent ; blades 2-8 dm. long or more, 1-4 cm. wide: panicle 

 3-6 dm. long: spikelets 3-4 mm. long. — Hammocks, U. keys, L. keys, L. S. keys. 

 — {Ber., Bah., Cuba, Ant.) 



^l 8. P. agrostoides Muhl. Stems 4-8 dm. tall, much-branched, compressed : 

 leaf -blades 3 dm. long or more, 4-8 mm. wide: panicle pyramidal, 1-3 dm. 

 long: spikelets 1.5-2 mm. long. — Lime-sinks, L. keys. — [E. K.] 



y ' 12. LASIACIS A. Hitchc. Shrubs vdXh. erect or reclining stems and 

 branches, and flat leaf -blades. Spikelets very thick, often globular, paniculate, 

 obliquely articulated to the pedicels. Scales 4^ the 3 outer papery, shining, 

 many-nerved, usually woolly at the apex, the first one less than i as long as the 

 spikelet : fourth or fruiting scales bony-indurated, woolly at the apex, enclosing 

 a palet of similar texture and a perfect flower. 



i/.-;. 1. L. divaricata (L.) A. Hitchc. Stems 2-3 m. tall, reclining: leaves crowded 

 and numerous; sheaths overlapping, ciliate on the margin; blades spreading or 

 ascending, glabrous, acuminate, the larger ones 8-10 cm. long, 13-35 mm. wide: 

 panicle 1 dm. long or less: spikelets 4-5 mm. long, the first scale very broad, 

 clasping the base of the spikelet. — Hammocks, U. keys, L. keys. — [E. K.] — 

 ■{Bah., Cuba, Ant.) — Small-cane. 



2- ^ 13. CHAETOCHLOA Scribn. Erect or diffuse plants with dense terminal 

 cylindric spike-like or narrowly thyrsoid panicles. Spikelets with 1, or a 

 cluster of 2-several sterile barbed bristle-like persistent branches. Three outer 

 scales membranous, the fourth scale usually shorter than the spikelet, char- 

 taceous, glabrous, shining, finally indurated. — Foxtail. Foxtail-grass. 



Inflorescence with the spikelets racemosely arranged : bristles 5-16 at the base of each 

 spikelet, involucrate. 

 Infloreseence stout : bristles exceeding twice the length of the spikelet. 



1. C. imberMs. 

 Inflorescence slender : bristles equalling or twice the length 



of the spikelet. 2. C. gracilis. 



Inflorescence with the spikelets in clusters or on branches : 

 bristles 1-3 at the base of each spikelet, not involucrate. 

 Second scale of the spikelet as long as the flowering scale 



or very nearly so. 3. C. magna. 



Second scale manifestly shorter than the flowering scale. 



Spikelets 3 mm. long or more. 4. C. macrosperma. 



Spikelets less than 3 mm. long. 5. C. caudata. 



V-^1. C. imberbis (Poir.) Scribn. Stems 3-7 dm. tall, slender: leaf -blades 1-3 dm. 

 long, 3-7 mm. wide, the upper surface often with a few long hairs at the base: 



