MANUAL OF THE GRASSES OF THE UNITED STATES 



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8. Panicum werneri Scribn. (Fig. 1280.) Vernal phase similar to 

 that of P. linearifolium, the culms usually stiff er, blades firmer, shorter 

 and wider (15 cm long or less) ; nodes usually sparingly pilose; sheaths 

 glabrous; spikelets 2.1 to 2.4 mm long, nearly or quite glabrous. 

 Autumnal phase similar to the vernal, sometimes late in the season 

 bearing simple branches from the lower nodes. 01 — Sterile woods 

 and knolls, Quebec and Maine to Minnesota, south to Virginia, 

 Kentucky, and Texas (fig. 1281). Intergrades with P. linearifolium. 



Figure 1278.— Panicum linearifolium. Two 

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



Figure 1279. — Distribution of 

 Panicum linearifolium. 



2. Laxiflora. — Tufted, erect to spreading; foliage aggregate toward 

 base, light green, soft, the basal bladesnot in distinct rosettes 

 in autumn; ligules nearly obsolete; primary panicles long-ex- 

 serted; spikelets obovate, obtuse, turgid, 5- to 7-nerved. Au- 

 tumnal phase branching near base, forming close flat tufts, with 

 reduced panicles. 



9. Panicum laxiflorum Lam. (Fig. 1282.) Vernal culms 20 to 60 

 cm tall, erect or geniculate below; nodes bearded with reflexed hairs; 

 sheaths retrorsely pilose; blades 10 to 20 cm long, 7 to 12 mm wide, 

 glabrous or sparsely ciliate; panicle 8 to 12 cm long, lax, few-flowered, 

 the lower branches often reflexed; spikelets 2.2 to 2.3 mm long, 

 papillose-pilose. Autumnal blades scarcely reduced, much exceeding 

 the secondary panicles. % — Rich or damp woods, South Carolina 

 to Florida and Alabama (fig. 1283). 



10. Panicum xalapense H.B.K. (Fig. 1284.) Vernal culms and 

 blades on the average shorter than in P. laxiflorum, the blades pilose 

 on one or both surfaces or nearly glabrous, usually short-ciliate ; spike- 



Figure 1280.— Panicum werneri. 

 Two views of spikelet, and floret, 

 X 10. (Type.) 



Figure 1281.— Distribution of 

 Panicum werneri. 



lets 1.9 to 2 mm long, pilose. Autumnal phase with usually denser 

 tufts and shorter blades. 01 — Woods, Maryland to Illinois and 

 Missouri, south to Florida and Texas; Mexico; Guatemala; Santa 

 Domingo. Originally described from Xalapa (Jalapa), Mexico (fig. 

 1285). Panicum xalapense var. strictirameum Hitchc. and Chase. 

 Vernal panicles more compact, branches ascending, spikelets 1.7 

 mm long; blades shorter, narrower. Oi — Dry woods, Coastal 

 Plain, South Carolina to Texas. 



