12 



POACEAE. 



Spikelets disposed singly or in pairs in one-sided racemes, the pedicels short. 



I. Paspaloidea. 

 SpikeletF in panicles, but not borne in one-sided racemes, the 

 pedicels short or long. 

 Basal leaf-sheaths round or but little flattened, not keeled. 

 Fourth scale smooth. 



Rootstocks and stolons naked or with few large 



scales : sand-binders. 

 Rootstocks, at least when young, and stolons covered 

 with numerous small broad acute scales. 

 Fourth scale transversely rugose. 

 Basal leaf-sheaths much compressed, broad, keeled, often 

 equitant. 



II. Halophila. 



III. ViEGATA. 



IV. Maxima. 



Tribe I. PASPALOIDEA. 



Fourth scale of the spikelet smooth. 



Fourth scale transversely rugose ; usually the outer scales of 

 the spikelets with anastomosing veinlets. 

 Branches of the panicle terminated by a spikelet. 



Spikelets broadly obovoid, 2.5-3 mm. long, obtuse or 

 acutish : anastomosing veinlets numerous and prom- 

 inent. 

 Spikelets oval, about 4 mm. long, acute or acuminate : 

 anastomosing veinlets few and faint. 

 Branches extending beyond the spikelet as an awn-like 

 projection. 



Tribe II. HALOPHILA. 



Large grass with acuminate spikelets 5-6 mm. long. 



Tribe III. 

 Stifif grasses with ample panicles. 



VIRGATA. 



Tribe. IV. MAXIMA. 

 Tall stout grasses with large leaves and ample panicles. - 



AGROSTOIDEA. 



V. Ageostoidea. 



1. P. geminatutn. 



2. P. fasciculatum. 



3. P. adspersum. 



4. P. Chapmanii, 



5. P. amarulum. 



6. P. virgatum. 



7. P. maximum. 



8. P. agrostoides. 



Tribe V. 

 Tufted grasses without rootstocks. 



1. P. geminatnin Forsk. Stems 6-12 dm. long, usually clothed with sheaths 

 below: leaves glabrous; blades 2.5 dm. long or less, 6-10 mm. wide: racemes 

 10-20, one-sided, the rachis broadly winged, appressed, 2-3.5 cm. long: 

 spikelets about 2.5 mm. long, ovate, acute, glabrous, singly disposed in 2 rows, 

 the first scale broader than long and clasping the spikelet at its base, truncate 

 at the apex, the fourth scale not transversely wrinkled. — Hammocks and cul- 

 tivated grounds, U. keys, L. keys. — {Bah., Ctiha, Ant.) 



2. P. fasciculatum Sw. Stems tufted, decumbent, finally branching at the base 

 and often rooting at the lower nodes, glabrous, 8-8 dm. long: leaf-sheaths 

 glabrous or pubescent ; blades 2.5 dm. long or less, 8-20 mm. wide, glabrous or 

 Ijubescent: panicle 1-2 dm. long, its branches ascending or nearly erect: 

 spikelets usually borne in pairs on one side of the branches on frequently 

 bristle-bearing pedicels, brown or green, 2.5-3 mm. long, broadly obovoid, 

 turgid, glabrous, obtuse, the second and third scales with anastomosing veinlets, 

 the fourth scale transversely rugose. — Hammocks, L, keys. — {Bah., Cuba, Ant.) 



3. P. adspersum Trin. Stems 4-6 dm. tall, decumbent, glabrous, branching 

 below: leaf-sheaths glabrous; blades 2 dm. long or less, 1.5-2 cm. wide, gla- 

 brous: panicle 1-2 dm. long, its branches ascending or nearly erect: spikelets 

 usually borne in pairs on one side of the branches, green, glabrous or pub- 

 escent, oval, abruptly acuminate, about 4 nmi. long, the second and third scales 

 with a few anastomosing veinlets, the fourth scale transversely rugose. — Ham- 

 mocks and cultivated grounds, L. keys.— [E. K.]—{Bah., Cuba, Ant.) 



4. P. Chapmanii Yasey. Glabrous or nearly so: stems 3-6 dm. tall: leaf- 

 blades 3 dm. long or less, 4-6 mm. wide, long-acuminate: inflorescence 1.5-2.5 



