to the Rocky Mountains. 229 



an inch long 1 below, diminishing in length upward, bibracteate in the mid- 

 dle. Calyx 5-leaved ; leaflets equal, imbricate, ovate, acuminate, brown, 

 bordered with white, about one sixth as long as the corolla, very smooth. 

 Corolla bilabiate, smooth, purple; tube scarcely ventricose ; upper lip 2- 

 lobed, lower lip S-lobed ; lobes all roundish. Stamens four, with a fifth 

 sterile, didynamous ; filaments smooth ; anthers 2-Iobed, smooth ; lobes 

 divaricate ; sterile filament as long as the shorter fertile ones, smooth, ob- 

 tuse. Germen ovate, acute, 2-celled. Style filiform, smooth, persistent ; 

 stigma simple. 



Hab. Near the Rocky Mountains. 



Obs. A beautiful species, allied to P. frutescens of Lam- 

 bert and Pursh. It recedes from the character of Pentstemon 

 in its smooth sterile filament, but it appears more nearly to re- 

 semble that genus than Chelone. 



316. P. gracile, JVutt. gen. ii. p. 52. Along the Platte. 



317. P grandiflorum, JYutt. in Fras. Cat. 1813. Ejusd. 

 gen. ii. p. 53. P. Bradburii, Pursh Jl. supp. p. 738. Mouth of 

 the Platte to the Rocky Mountains. Also on the Canadian. 

 Flowers May — Aug* 



318. P. albidum, Nutt. gen. ii. p. 53. Near the Rocky 

 Mountains. 



319. P. erianthera, JVutt. gen. ii. p. 52. P. glabra 

 Pursh. fl. supp. Sources of the Platte. 



320. P. cristatum, JVutt. gen. 1. c. P. erianthera. 

 Pursh fl. supp. 1. c. Forks of the Platte. 



321. P. c(eruleum, JVutt. gen. 1. c. ? P. imberbis, 

 Kunth syn. ii. p. 122 ? 



Obs. Radical leaves lanceolate ; cauline linear, all very 

 entire ; peduncles 2-flowered ; segments of the calyx ovate, 

 obtuse or slightly mucronate ; anthers smooth ; sterile fila- 

 ment shorter than the fertile stamens, retuse, and nearly 

 smooth at the apex. Whole plant very smooth and slightly 

 glaucous. The flowers in my specimens are faded too much 

 to ascertain what was their original colour. They appear to 

 have been purple. 



