122 Aveneae Sphenopholis 



First glume less than a third as wide as the second; lemmas smooth (rarely 



slightly scabrous at the apex) ; anthers mostly 0.5-0.8 mm long. 



Spikelets 3-4 mm long; second glume narrowly obovate or wider, subacute or 



blunt at the apex; rachilla-internode below the second floret usually about 



1 mm long; anthers mostly 0.5-0.6 mm long; panicles usually lax. (A rare 



form of this species.) 2. S. intermedia. 



Spikelets mostly about 2.5 mm long (rarely up to 3 mm or longer) ; second glume 



broadly obovate, about as wide as long, broadly rounded or truncate at the 



apex; rachilla-internode below the second floret about 0.5 mm long; anthers 



about 0.8 mm long; panicles usually contracted. .3a. S. obtusata var. pubescens. 



Sheaths and blades glabrous, smooth or scabrous. 



Spikelets 3-4 mm long; second glume narrowly obovate or wider, subacute or blunt 

 at the apex; rachilla-internode below the second floret usually about 1 mm 

 long; anthers mostly 0.5-0.6 mm long; panicles usually lax. (Our common 



form of the species.) 2. S. intermedia. 



Spikelets usually about 2.5 mm long (rarely up to 3 mm or longer) ; second glume 

 broadly obovate, about as wide as long, broadly rounded or truncate at the 

 apex; rachilla-internode below the second floret about 0.5 mm long; anthers 

 about 0.8 mm long; panicles usually contracted 3. S. obtusata. 



1. Sphenopholis nitida (Spreng.) Scribn. Map 195. Rather frequent in 

 the unglaciated area of southern Indiana and rare in the northern part 

 of the state. It is generally found on black and white oak ridges and 

 rarely with beech. It prefers a rich soil of weathered sandstone and it may 

 be entirely absent in neutral or alkaline soils. 



A glabrous form of this species has been described but it may not occur 

 in Indiana as all of my 41 specimens are copiously pubescent. 

 Mass. to N. Dak., southw. to Fla. and Tex. 



2. Sphenopholis intermedia (Rydb.) Rydb. {Sphenopholis pallens of 

 recent authors.) Slender Wedgegrass. Map 196. Infrequent to frequent 

 throughout the state. It prefers a dry soil and is found in many habitats. 

 Usually frequent in beech and sugar maple woods, white oak woods, and 

 white oak and black oak woods; less frequent in moist or wet woodland, 

 bogs, and fallow fields and along railroads. I have a specimen with pubes- 

 cent sheaths and leaves, which was found growing in sphagnum in a 

 decadent tamarack bog just east of Pokagon State Park, Steuben County. 

 This is the only pubescent specimen I have out of 79 Indiana specimens. 



Newf. to B. C, southw. to Fla. and Ariz. 



3. Sphenopholis obtusata (Michx.) Scribn. Prairie Wedgegrass. Map 

 197. Infrequent to local throughout the state. Its habitat varies from the 

 crests of ridges in the "knobs" to low sand ridges and old lake and river 

 bottoms. 



Maine to B. C, southw. to Fla., Ariz., Calif., and Mex. 



3a. Sphenopholis obtusata var. pubescens (Scribn. & Merr.) Scribn. 

 This is a form with the sheaths and upper and lower surface of the leaves 

 pubescent. I have it from only the southern part of the state where it 

 occurs in Crawford, Perry, and Posey Counties. I segregate this form 

 from the species for the benefit of other workers who may be interested 

 in the geographical distribution of the form. 



