548 GltAMlNK.lC. (r.lt.VSS lAMIl.V.) 



48. AMPUICARPl M. Ppikelfts of two kind* ; ono aisposcJ in a tcrmlnnl |!qd1cIo, perfect but 



M>Mom fruiting ; tlie other fruitful, on long solitary radical iictliinclcii. 



• • Glume!) 2, tho lower one often minute, rarely wanting. 



49. PAXICUM. Spikclets single, without a bristly or spiny involucre. 



CO. ?KT.VUI.\. Spikclets crowded in Kjiike-like panicle.s, subtended by a bristlc-liko liiTolucro. 



51. CKNl'linUS. Sjiikeleta single, or few iu a cluster, enclosed in an induniti-d and spiny in- 



volucre. Spikclets spiked. 



52. STKNOTAI'IIRUM. Spikes and spikclets mostly us in llottba'liiu, but the flowers as in 



Panioum. 



Tribe IX. ROTTBCELI.iI AC EiE. — Spikclets 1 - 2-flowcri'd, by pairs, imbedded in 

 an excavation nf the thick and juinted nichis, one stalked and imperfect, tho other sessile 

 and perfect ; or the upper spikclets all staminate and the lower pistillate. I.,ower glume 

 coriaceous or cartilaginous. I'aleoc awiiless. 



53. ROTTBfELLI.\. Spikclets 2 on each joint, one stalked and sterile, the other se.ssilo and 



perfect. 



64. MAXISURIS. Spikclets 2 on each joint, the one at the top of the joint sterile, tho other 

 at the base globose and fertile. 



55. TUIPSACUM. Upper .spikclets by pairs, all staminate ; the lower ones single, and pis- 

 tillate. 



Tribe X. AXDROPOGONEjE. — Spikclets 2-3 on each jaint of the slender hairy or 



plumose rachis. Glumes more rigid than the thin-awued palca;. 

 66. ANDllOPOGO.V. Spikclets 2 on each joint of the plumose or hairy rachis, one sessile and 



perfect, the other stalked and imperfect or rudimentary. 

 57. KlUAXTIIUS. Spikclets 2 on each joint of the rachis, both fertile and surrounded by a 



hairy involucre. 

 68. SOUGIIUM. Spikelets panicled, 2-3 together, the lateral ones rudimentary. 



1. LEERSIA, Swartz. False Rice." 



Perennial aquatic or niarsii grasses, with tlie leaves and sheaths roughened 

 with minute recurved points, the l-flowered (whitish) spiicelcts crowded in 

 1-sided panicled racemes. Pedicels jointed. Glumes none. Palca; 2, charta- 

 ceous, strongly compressed, fringed on the keel, the lower one much wider. 

 Stamens 1-6. Stigmas 2. Grain compressed. 



1. L. oryzoides, Swartz. Panicle large, diffuse; spikelets oblong, flat, 

 loosely imbricated ; stamens 3. — Ditches and swamps, Florida, and northward. 

 July and Aug. — Culm 3° -4° long, commonly prostrate at the base. Leaves 

 spreading. Base of the panicle mostly enclosed in the sheath of the subtending 

 leaf Spikclets strongly fringed, about 3" long. 



2. L. Virginiea, WiUd. Panicle nearly simple, the lower branches spread- 

 ing ; spikclets small, concave, sparingly fringed, closely imbricated; stamens 

 1-2. (L. imbricata. Lam.?) — Swamps and margins of streams, Florida, and 

 northward July and Aug. — More slender than the last, and with spikelets 

 half as large. 



3. L. lenticularis, Michx. Panicle diffuse ; spikelets oval, flat, strongly 

 fringed, clo.scly imbricated ; stamens 2. — I'onds and swamps Florida to North 

 Carolina, and westward. Aug —Culm 2° -3° long. Leaves widely spread- 

 ing, somewhat glaucous. Spikelets 3" long. 



