HOW TO KNOW THE GRASSES 



4a. Each raceme* of spikelets consisting of many pairs of spikelets; 

 racemes solitary or variously grouped 5 



4b. Each raceme* consisting of 1 — 3 pairs of spikelets; racemes grouped 

 into an open or dense panicle 15 



5a. Both spikelets of each pair alike and with perfect florets 6 



5b. One spikelet of each pair perfect, the other either staminate, sterile, 

 reduced in size, of a different shape, or nearly absent 7 



6a. Spikelets with awns; wild plants. Fig. 340. 



SILVER PLUMEGRASS Erianthus alopecuroides (L.) Ell. 



Figure 340 



Perennial; culms strong and tall, 1 — 3 

 m. long, arising from short, scaly rhizomes. 

 The nodes, upper portions of the sheaths, 

 and peduncles are oppressed-hairy. The 

 dense silky-hairy elliptical panicles are 20 

 — 30 cm. long. Each yellowish spikelet 

 bears a tuft of long silvery or purplish 

 hairs from the base, as well as a few 

 hairs on the upper portions of the glumes. 

 Spikelets 5 — 6 mm. long, with a flattened 

 and twisted awn 1 — 1.5 cm. long. The 

 rachis breaks up into individual joints 

 when ripe. Open woods, wet low ground, 

 hammocks. September — October. 



Erianthus contortus Ell. is similar, but has dark brown glimies. 



Erianthus giganteus (Walt.) Muhl. (E. saccharoides) is similar but 

 has straight, untwisted awns which are not flattened in crosss section. 



♦According to strict definition, these inflorescence branches are not racemes, 

 because they have some sessile spikelets, but this term is usually used. 



177 



