HOW TO KNOW THE GRASSES 



39a. Spikelets glabrous, narrowly elliptical. 1.8 — 2.2 mm. long; leaf 

 blades not hairy on the margins. Fig. 321. 



Panicuzn dichotomum L. 



Perennial; tufted; plants erect, 30 — 50 cm. 

 tall, glabrous or with a ring of hairs on the 

 lower nodes; terminal panicles in June, 4 — 9 

 cm. long, with spreading branches. Later 

 the culms become much branched from the 

 middle nodes, appearing Uke Uttle trees and 

 sometimes falling from their weight. The sec- 

 ondary panicles are small, with few spikelets. 

 They extend sUghtly above the leaves of the 

 branches. Widespread and common in rocky 

 woods and on brushy land. 



Panicum microcarpon Muhl. has strongly 

 bearded nodes and tiny spikelets, 1.5 — 1.7 

 mm. long. Moist woods, meadows, and 

 swamps. 



Figure 321 



39iD. Spikelets minutely hairy, broadly obovoid at maturity, 1.5 — 1.8 

 mm. long; leaf blades 7 — 14 mm. wide, with long marginal hairs 



at the base. Fig. 322. 



Panicum sphaerocarpon Ell. 



Perennial; tufted; culms 20 — 55 cm. long, 

 erect or spreading; plants glabrous except 

 for the few hairs at the base of each leaf 

 blade, and often somewhat glaucous. Leaf 

 blades rather broad, the top one 4 — 9 mm. 

 in width. The broad panicle is less than 

 twice as long as wide. Dry open ground 

 and thin woods. Terminal panicles in 

 June and July. 



Panicum polyanthes Schult. has a longer, 

 elhptical panicle, 2 — 4 times longer than 

 wide, and an uppermost leaf 9 — 28 mm. 

 wide. Open woods and damp ground. 

 Southern New England to Oklahoma and 



Figure 322 southward. 



168 



