MANUAL OF THE GRASSES OF THE UNITED STATES 



661 



M6LLE (Vasey) Hitchc. and Chase. Differing from P. ooscii in the 

 downy-villous culms and sheaths and the velvety blades. 01 

 About the same range as the species. 



SUBGENUS 3. EUP^NICUM Godr. 



Spikelets in open or condensed panicles or in spikelike racemes, the 

 branchlets not produced as bristles (the naked tip forming a short 

 point in Geminata) ; not presenting vernal and autumnal phases 

 of a distinctive character, with winter rosettes of leaves different 

 from the culm leaves. 



1. Geminata. Subaquatic glabrous perennials; inflorescence of sev- 



eral erect, spikelike racemes distant on an elongate axis; rachis 

 ending in a short naked point; spikelets subsessile, abruptly 

 pointed, glabrous, first glume truncate; fruit transversely 

 rugose. 



111. Panicum geminatum Forsk. (Fig. 1468.) Culms tufted, 25 

 to 80 cm tall, scarcely succulent, often decumbent at base or with 

 stolons rooting at the nodes; blades 10 to 20 cm long, 3 to 6 mm wide, 

 flat, or involute toward the apex; panicle 12 to 30 cm long, the 

 appressed racemes 12 to 18, the lower 2.5 to 3 cm long, the upper 

 gradually shorter ; spikelets 2 .2 to 2 .4 mm long, 5-nerved. 2L Moist 

 ground or shallow water, mostly near the coast, southern Florida, 

 Louisiana, and Texas; warmer regions of both hemispheres. 



112. Panicum paludivagum Hitchc. and Chase. (Fig. 1469.) 

 Resembling P. geminatum, but the culms elongate from a long creeping 

 rooting base, rather succulent, as much 



as 2 m long, the lower part submerged, 

 loosely branching; blades 15 to 40 cm 

 long, scabrous on the upper surface; 

 spikelets 2.8 to 3 mm long, faintly 

 3-nerved; fruit obscurely rugose. 21 

 More or less submerged in fresh- 

 water rivers and lakes, Florida, Texas; 

 Mexico, Guatemala. 



2. Purpurascentia. Stoloniferous ro- 



bust perennial; a single species 

 introduced. 



113. Panicum purpurascens Eaddi. 



PARA GRASS. (Fig. 1470.) Culms decumbent and rooting at base, 

 2 to 5 m long, the nodes densely villous; sheaths villous or the upper 

 glabrous, densely pubescent on the collar; blades 10 to 30 cm long, 

 10 to 15 mm wide, flat, glabrous; panicle 12 to 20 cm long, the 

 rather distant subracemose densely flowered branches ascending or 

 spreading; spikelets subsessile, 3 mm long, elliptic, 5-nerved, glabrous; 

 fruit minutely transversely rugose. Q|. (P. barbinode Trin.) Culti- 

 vated and waste ground in moist soil, borders of rivers, marshes, and 

 swamps, Florida, Alabama (Mobile), Texas; Oregon (Linn ton); 

 throughout tropical America at low altitudes. Commonly cultivated 

 in tropical America as a forage grass, being cut for green feed. It 

 probably was introduced into Brazil at an eary date from Africa. 



3. Fasciculata. Branching annuals; blades flat; ligules not more than 



1 mm long; panicles of ascending spikelike racemes along an 

 angled axis; spikelets subsessile, abruptly pointed strongly 5- to 

 7-nerved; fruit transversely rugose. 



FIGURE 1469. Panicum paiudivagum. Two 

 views of spikelet, and floret, X 10. (Type.) 



