080 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Figure 1024.- 



brous or nearly so; panicle 6 to 12 cm. 

 long; spikelets 4 to 4.5 mm. long, 

 about half as wide, papillose-pubes- 

 cent. Autumnal phase about as in P. 

 latifolium, finally top-heavy-reclining. 

 21 — Woods, Massachusetts to Wis- 

 consin and Oklahoma, south to north- 

 ern Florida and Texas. Panicum 

 boscii var. molle (Vasey) Hitchc. 

 and Chase. Differing from P. boscii in 

 the downy-villous culms and sheaths 

 and the velvety blades. % 

 About the same range as the species. 



Subgenus 3. Eupanicum Godr. 



Spikelets in open or condensed pan- 

 icles or in spikelike racemes, the 

 branchlets not produced as bris- 

 tles (the naked tip forming a 

 short point in Geminata); not 

 presenting vernal and autumnal 

 phases of a distinctive character, 

 with winter rosettes of leaves dif- 

 ferent from the culm leaves. 



1. Geminata. — Subaquatic glabrous 

 perennials; inflorescence of sev- 

 eral erect, spikelike racemes dis- 

 tant on an elongate axis; rachis 

 ending in a short naked point; 

 spikelets subsessile, abruptly 

 pointed, glabrous, first glume 

 truncate; fruit transversely ru- 

 gose. 

 116. Panicum geminatum Forsk. 

 (Fig. 1025.) Culms tufted, 25 to 80 

 cm. tall, scarcely succulent, often de- 

 cumbent at base or with stolons root- 

 ing at the nodes; blades 10 to 20 cm. 

 long, 3 to 6 mm. wide, flat, or in- 



-Panicum boscii. Two views of spikelet, and floret, 

 X 10. (Type.) 



volute 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. % — 

 Moist ground or shallow water, 

 mostly near the coast, southern Flor- 

 ida, Louisiana, Texas, and Okla- 

 homa; warmer regions of both hemi- 

 spheres. 



117. Panicum paludivagum Hitchc. 

 and Chase. (Fig. 1026.) 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 sur- 

 face; spikelets 2.8 to 3 mm. long, 

 faintly 3-nerved; fruit obscurely ru- 

 gose. % — More or less submerged 

 in fresh-water rivers and lakes, Flor- 

 ida, Texas; Mexico, Guatemala. 



2. Purpurascentia. — Stoloniferous ro- 

 bust perennial; a single species 

 introduced. 



118. Panicum purpurascens Raddi. 

 Para grass. (Fig. 1027.) Culms de- 

 cumbent 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 sub- 

 racemose densely flowered branches 

 ascending or spreading ; spikelets sub- 

 sessile, 3 mm. long, elliptic, 5-nerved, 

 glabrous; fruit minutely transversely 



