702 



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



Figure 1069. — Panicum longifolium. Two views of 

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



Figure 1070. — Panicum combsii. Two views of spike 

 let, and floret, X 10. (Type.) 



Figure 1071. — Panicum anceps. Spikelet and floret, 

 X 10. (Type.) 



Figure 1072. 



-Panicum rhizomatum. 

 floret, X 10. (Type.) 



Spikelet and 



near the summit; ligule fimbriate- 

 ciliate, 2 to 3 mm. long; blades elon- 

 gate, 2 to 5 mm. wide, pilose on the 

 upper surface near the base; lateral 

 panicles few or none, the terminal 10 

 to 25 cm. long, the branches slender, 

 ascending; spikelets 2.4 to 2.7 mm. 

 long. % — Moist sandy ground, 

 Massachusetts to Florida and Texas 

 to Indiana and Tennessee. 



161. Panicum combsii Scribn. and 

 Ball. (Fig. 1070.) Resembling P. 

 longifolium; sheaths glabrous or 

 nearly so; ligule less than 1 mm. long; 

 blades on the average shorter; spike- 

 lets 3 to 3.5 mm. long, acuminate. 

 % — Margins of ponds and wet 

 woods, southeastern Virginia; Georgia 

 and Florida to Louisiana. 



162. Panicum anceps Miclrx. (Fig. 

 1071.) Culms 50 to 100 cm. tall, with 

 numerous scaly rhizomes; sheaths 

 glabrous or pilose; blades elongate, 4 

 to 12 mm. wide, pilose above near the 

 base; panicles 15 to 40 cm. long, the 

 slender, remote branches somewhat 

 spreading, bearing short mostly ap- 

 pressed branchlets with rather 

 crowded somewhat curved subsecund 

 spikelets, set obliquely on their pedi- 

 cels; spikelets 3.4 to 3.8 mm. long. 

 % — Moist sandy soil, New Jersey 

 to Kansas, south to Florida and 

 Texas. 



163. Panicum rhizomatum Hitchc. 

 and Chase. (Fig. 1072.) Resembling 

 P. anceps; culms less robust, the rhi- 

 zomes more slender and numerous; 

 sheaths densely to sparsely villous, 

 especially at the summit; blades usu- 

 ally pubescent on both surfaces; pan- 

 icles more or less contracted; spike- 

 lets 2.4 to 2.8 mm. long. % — 

 Moist sandy woods and savannas, 

 Coastal Plain, Maryland to Florida 

 and Texas; Tennessee. 



Moist soil, Connecticut to Missouri, 

 south to Georgia and Texas. 



160. Panicum longifolium Ton. 

 (Fig. 1069.) Culms rather slender, 35 

 to 80 cm. tall, in dense tufts, usually 

 surrounded by basal leaves nearly 

 half as long; sheaths usually villous 



12. Laxa. — Slender perennials; culms 

 compressed; ligules minute; 

 spikelets short-pediceled, 5- 

 nerved, glabrous, the palea of the 

 sterile floret becoming enlarged 

 and indurate, expanding the 

 spikelet at maturity; fruit min- 



