1921] NATURAL SCIENCES OF PHILADELPHIA. 483 



only rudimentary. Leaf-blades ovate, obtuse to 

 acutish, mostly shorter than the inter nodes. 



5. P. fendleri. 



EE. Corolla glandular puberulent externally and internally. 

 Anther-cells as wide as long. Sterile filament slender, 

 not or but slightly enlarged distally. Leaves usually 

 serrate, thinner, firm, membranous. Plants not glau- 

 cous. III. Albtdi. 

 Corolla 15-20-25 mm. long, white or violet-tinged, its 

 posterior lobes united less than half their length. 

 Anthers dark violet-gray. Capsule 10-15 mm. 

 long. Stem -leaves broadly linear to lanceolate, en- 

 tire or serrate. 

 Leaves permanently more or less canescent, lanceo- 

 late, those of the basal tufts narrowly ovate. Cap- 

 sule ellipsoid-ovate to ovate in outhne, 5-7 mm. wide. 



6. P. alhidus. 



Leaves glabrous (except for minute line along midrib 

 above), broadly hnear, those of the basal tufts 

 broadly or spatulate-linear. Capsule globose-ovate 

 in outline, 7-8 mm. wide. 



7. P. guadalupensis. 

 Corolla 25-50 mm. long, violet-purple to white, its 



posterior lobes united more than half their length. 

 Anthers gray. Capsule 15-20 mm. long. Stem- 

 leaves lanceolate to ovate, mostly serrate. 

 Corolla 25-40 mm. long, its throat gradually expand- 

 ing from the tube, moderately inflated and not 

 narrowing to orifice. Sepals acuminate. 



8. P. triflorus. 



Corolla 40-50 mm. long, its throat abruptly expand • 

 ing from the tube, strongly inflated and narrow- 

 ing to orifice. Sepals acutish to slightly acum- 

 inate. 

 Corolla pale-purple, more widely inflated, usually 

 obscurely glandular within. Foliage pale-green. 



9. P. cobaea. 



Corolla deep-purple, less widely inflated, more 

 evidently glandular within. Foliage deeper green. 

 9a. P. cobaea purpureus. 

 DD. Corolla-throat more or less flattened, two-ridged within, 

 anteriorly (scarcely so in P. tubiflonis). Seeds .8-1 mm. 

 long. 

 E. Corolla white, not lined, glandular puberulent within on 

 all sides; the throat slightly inflated and scarcely or 

 not two -ridged within, the lobes widely spreading. 

 Stem and leaves glabrous, the latter entire or very 

 nearly so. IV. Tubiflori. 



10. P. tubiflorus. 



