52 



Rhodora 



[March 



g. Spinules numerous, very coarse and bristly; 

 some spikelets awned; panicle open or 



moderately dense 5. E. mvrieata. 



g. Spinules few, short and inconspicuous; 

 spikelets awnless; panicle usually dense. 



var. ludoviciana. 

 f. Spikelets small or medium (2.5) 2.8-3.4 mm. 

 long, rarely longer in var. multiflora due 

 to the long point, 1.4-1.8 mm. broad; an- 

 thers (0.3) 0.4-0.7 mm. long; (spikelets 

 awnless or with short awn-tips; panicle 

 normally rather dense). 

 g. Spinules not very bristly, slightly swollen 

 at base, the dorsal ones of the upper 

 glume minute or none; panicle green or 

 purple-tinged; (anthers 0.5 (0.4-0.6) mm. 



long) var. occidentalis. 



g. Spinules long, coarse and bristly, strongly 

 swollen at base, the dorsal well devel- 

 oped, spreading; panicle usually dark 

 violet-purple or the albinos green. 

 h. Spikelets apiculate or short-acuminate, 

 very rarely subulate-tipped; panicle 

 dense, 7-20 cm. long; anthers 0.3-0.5 



(-0.6) mm. long var. microslachya. 



h. Spikelets long-acuminate, often subu- 

 late-tipped; panicle longer and looser, 

 (9-) 15-10 cm. long; anthers 0.6-0.7 



nun. long var. multiflora. 



d. Spikelets ellipsoid or broadly ellipsoid, more 

 densely aggregated; coriaceous lemma elliptical; 

 (spikelets with short purple awns or rarely al- 

 most awnless; spinules mostly uniform in size 

 on the various ribs, slender, ascending, scarcely 

 swollen at base; lower palet present; coriaceous 

 lemma subacute; nodal and branch-setae of the 

 panicle moderately developed). 

 e. Spikelets 2.8-3.2 mm. long; anthers 0.6 (0.5- 



0.8) mm. long 6. E. echinata. 



e. Spikelets 3.5 mm. long; anthers 1-1.2 mm. long. 



var. decipiens. 

 c. Upper glume short-awned, very rarely awnless (see 

 also sometimes E. muricata) ; lower lemma with a 

 long purple awn; spikelets ellipsoid; anthers 0.9-1 

 (0.6-1.2) mm. long; (spikelets softly but plainly 

 echinate; spinules equally developed on the vari- 

 ous ribs or stronger on the lateral; coriaceous 

 lemma elliptical, subacute; lower palet present; 

 panicle broad, dense, usually purple, nodding; the 

 nodal and branch-setae well developed). 



d. Sheaths papillose-hispid and pubescent 7. E. Walteri. 



d. Sheaths glabrous forma laevigata. 



b. Spikelets 4.7-6 mm. long, ellipsoid, slightly or not at 

 all echinate, the spinules fine; (lower glume broad 

 subtruncate-aeute; upper glume acuminate or awn- 

 tipped; lower lemma short-awned; lower palet pres- 

 ent or absent; anthers 0.6-0.8 mm. long; panicle 

 narrow, with or without nodal and branch-setae). 



8. E. oplismenoides. 



