HOW TO KNOW THE GRASSES 



34b. Leaf sheaths and usually the blades conspicuously hairy. Fig. 317. 



Panicuin implicatum Scribn. 



Perennial; tufted; plants 15 — 75 cm. tall, 

 with open, pyramid-shaped terminal panicles 

 blooming in May and June. Later the plants 

 become much-branched, with loose axillary 

 tufts of short leafy branches, interspersed with 

 the short secondary panicles. Roadsides, old 

 fields, open woods, meadows, swamps. Very 

 common and widespread. Panicum implica- 

 tum is usually broken up into a number of 

 scarcely distinguishable "species" by other 

 authors. P. columbianum (see Fig. 324) is 

 quite similar. 



Figure 317 



35a. Plants smooth or somewhat hairy, never velvety to the touch 



.36 



35b. Culms, leaf blades, and sheaths softly velvety to the touch, gray- 

 ish; a smooth, sticky ring is present below each node. Fig. 318. 



Panicum scoparium Lam. 



Perennial; tufted; plants 80—130 cm. tall; leaf 

 blades large, 12—20 cm. long and 10—20 mm. 

 wide. The terminal panicles are open, elliptical, 

 up to 15 cm. long, produced in June and July. 

 Later the plants become branched, with loose 

 bunches of leaves in the axils of the sheaths of 

 the main culm. Th^ small secondary panicles 

 are partially concealed among these branches. 

 Low moist soil, mostly on the Atlantic Coastal 

 Plain and northward in the Mississippi Valley. 



Figure 318 



36a. Spikelets over 3 mm. long. 



37 



36b. Spikelets 2.7 mm. or less long. 



38 



166 



