484 PROCEEDINGS OF THE ACADEMY OF [PaRT III 



EE. Corolla white or pink, usually with lines of deeper 

 color, somewhat pubescent with glandless hairs within 

 over bases of anterior lobes, the throat inflated and 

 two-ridged within anteriorly. Leaves more or less ser- 

 rate. V. Graciles. 

 Corolla with throat much inflated and only slightly 

 two -ridged within anterior.y. Sepals acuminate, 

 more than one half length of capsule. Sterile 

 filament moderately bearded. 

 Anthers barbate. Corolla 25-35 mm. long, more 

 strongly inflated, white or slightly tinged or 

 lined with purple. Stem glabrous or nearly so, 

 semi-shining. 11. P. digitalis. 



Anthers glabrous. Corolla smaller, moderately in- 

 flated, more or less violet-purple. Stem finely 

 pubescent to glabrous, relatively dull. 

 Corolla 20-25 mm. long, usually light violet-purple. 

 Inflorescence narrower than long, in fruit 2-6 

 cm. wide, its cyme-branches of but two or three 

 nodes. Stem-leaves mostly oblong-lanceolate, 

 relatively less expanded at base, less serrate. 



12. P. pentstemon. 



Corolla 15-20 mm. longj violet-pink, paler within. 

 Inflorescence in fruit usually 6-12 cm. wide, its 

 cyme-branches of repeated nodes. Stem-leaves 

 usually much smaller, often somewhat expanded 

 at base, more sharply serrate. 



13. P. tenuis. 



Corolla with throat narrow, strongly two-ridged within 

 anteriorly. Sepals acute or triangular-acuminate, 

 less than or nearly one half length of mature cap- 

 sule. 

 Corolla 15-17 mm. long, white, its throat about as 

 long as the tube, the orifice not closed by the 

 anterior lip. Sterile filament moderately bearded. 

 Leaves below inflorescence relatively well -devel- 

 oped, so stem conspicuously leafy. 

 Free portions of posterior lobes of corolla upcurved. 

 Inflorescence 4-7 cm. wide. Stems puberulent 

 or pubescent. Basal leaves 7-10 cm. long, 

 obtuse to acute, crenate -serrate, the stem-leaves 

 obtusish to acuminate, all puberulent. Plants 

 forming small clumps of few stems. 

 Stem grayish-puberulent. 



14. P. arkansanus. 



Stem pubescent. Stem-leaves broader, nearly 

 ovate. 14a. P. arkansanus puhescens. 



