840 



SCROPHULARIACEAE 



Penstemon 



50 



Map 1823 



Penstemon calycosus Smal 



Throat of corolla narrow, flattened and strongly ridged within, the anterior lobes 



of the corolla projecting considerably beyond the posterior ones; sterile filament 



more densely bearded. 



Orifice to the throat of the corolla open; cells of anthers longer than wide; lower 



surface of leaves more or less short-pubescent or pubescent on the midrib and 



along the principal veins. 



Throat of corolla moderately inflated; corolla 20-32 mm long; lower surface of 



leaves sparsely pubescent all over with long hairs or only on the midrib 



and larger veins 6. P. canescens var. typicus. 



Throat of corolla slightly inflated; corolla 17-22 mm long; lower surface of 



leaves densely pubescent all over with short hairs 7. P. pallidns. 



Orifice to the throat of corolla closed by the uparching lower lip; corolla 23-28 

 mm long; cells of anthers about as wide as long; lower surface of leaves 

 usually soon glabrous or only the midrib with long hairs 8. P. hirsutus. 



1. Penstemon tubaeflorus Nutt. Tube Penstemon. Map 1822. I have 

 this species from only three places in two counties where I found it in dry 

 and very sandy soil on an open, oak, sand ridge and along the railroad 

 about 5 miles south of Vincennes. It was also collected in Vigo County 

 by Evermann. 



Ind. to Kans. and Tex. ; probably introduced in the Atlantic States from 

 Maine to Pa. 



2. Penstemon calycosus Small. Map 1823. This is our most common 

 species and could possibly be found in every county of the state, although 

 it is less frequent in our northern counties. While it prefers moist, alluvial 

 soil along streams and bases of slopes, it is found also on dry, wooded 

 slopes, along roadsides and railroads, and in fallow fields. 



Maine, Mich., to 111., and along the coast to Pa., southw. to n. Ala., Miss., 

 Mo., and Ark. 



3. Penstemon Digitalis Nutt. (Penstemon laevigatas var. Digitalis 

 (Sweet) Gray of Gray, Man., ed. 7 and Penstemon Digitalis (Sweet) Nutt. 

 of Britton and Brown, Illus. Flora, ed. 2.) Foxglove Penstemon. Map 

 1824. This species is somewhat frequent throughout the state in both 

 moist and dry soils in various habitats. It often forms large colonies, espe- 



