HOW TO KNOW THE GRASSES 



6a. Lemmas notched at the blunt apex, awnless, glabrous or nearly so. 

 Fig. 250. 



GREEN SPRANGLETOP Leptochloa dubia (H. B. K.) Nees 



Perennial; tufted; culms 50 — 100 cm. 

 long, tough, erect; leaf sheaths smooth; 

 blades flat or somewhat rolled or folded, 

 up to 10 mm. wide; panicles up to 15 

 cm. long, the spreading spikes 3 — 12 

 cm. long; spikelets 5 — 10 mm. long, usu- 

 ally with 5 — 8 or occasionally fewer 

 florets; lemmas oblong, blunt, the tip 

 notched, the midnerve sometimes pro- 

 truding. The plants sometimes bear 

 cleistogamous inflorescences hidden in 

 the sheaths. This species has some 

 value as a forage grass in the South- 

 west. Sandy or rocky open ground. 

 March — September. 



Figure 250 



6b. Lemmas tapering to a sharp point, awned, hairy on the nerves. 

 Fig. 251. 



Leptochloa fascicularis (Lam.) Gray 



Annual; tufted; culms 30 — 100 cm. long, 

 erect or horizontally spreading; plants be- 

 coming much-branched; leaf blades flat 

 or somewhat rolled; panicles rather stiff, 

 usually partly hidden in the leaf sheaths, 

 10 — 20 cm. long, the individual spikes up 

 to 10 cm. long; spikelets 7 — 12 mm. long, 

 with 6 — 12 florets; awns ranging from very 

 short to 4 — 5 mm. long. Moist or alkahne 

 soil, salt marshes, open ground. July — 

 September. This is an unusually widely- 

 ranging grass, extending southward 

 through the American tropics to Argen- 

 tina. It is sometimes placed in the genus 

 Diplachne. 



Figure 251 



133 



