146. Gramineae 347 



5. I'lanls annual; panicles 1 ()-!U) cm long; blades 2-J nun 



wide; sandy soil, local. July-Oct 



P. flexile (Gall.) Scribn. 



5. Plants perennial. 



6. Panicle loose, open, 20-50 cm long; blades 6-10 mm 

 wide; plants with long scaly rhizomes; along ditches, 

 or in moist soil, or woods in the s. and w. parts of 

 111., extending northward to Peoria and Henderson 

 counties. July- Sept P. anceps Michx. 



6. Panicle 3-8 cm long, not much exceeding or shorter 

 than the leaves, few-flowered; blades 2-5 mm wide, 

 often involute in drying; open woods. May- June 

 P. depaup( ratum Muhl. 



2. Spikelets less than 3 mm long. 

 7. Sheaths glabrous. 



8. First glume not more than one-fourth the length of the 

 spikelets, rounded at the apex; plants annual, mostly 

 glabrous; spikelets 2.5-3 mm long; fields and waste 



places, common. Aug. -Oct. Fall Panicum 



P. dichotomiflorum Michx. 



8. First glume more than one-fourth the length of the spike- 

 let; plants perennial. 

 9. Spikelets 1.5-1.6 mm long; blades 10-12 cm long, 8-15 

 mm wide, ciliate at base, otherwise glabrous; panicle 

 8-12 cm long; stem-nodes densely bearded with re- 

 flexed hairs; wet ground, s. 111. June-Aug 



P. inicrocarpon Muhl. 



9. Spikelets 2-2.5 mm long. 



10. Pedicels about halt the length of the spikelels; pan- 

 icles 10-30 cm long, the spikelets subsecund; plants 

 in dense tufts; moist groimd, locally throughout 

 111. except the n. counties. July-Oct. Munro Grass 



P. agrostoidcs Spreng. 



10. Pedicels longer than the spikelets, which are not at 

 all secund; panicles 4-12 cm long. 

 1 1 . Sheaths bearing pale glandular spots, the margins 

 glabrous; blades 8-11 mm wide; spikelets 2.3- 

 2.5 mm long, pointed; moist woods and thick- 

 ets, s. 111. June-July P. yadkinense Ashe 



11. Sheaths nol s])otted, ihe margins jiubescent; 

 blades 4-8 mm wide; spikelets 2 mm long, not 

 pointed; open woods, more common in s. 111., 

 but extending northward lo Peoria Go. May- 

 July. [P. harhulal inn Michx.] 



P. dichotomurti L. 



7. Sheaths pubescent. 



12. Spikelets lanceoloid, acuminate, 2-3 mm long; panicle 



