488 PROCEEDINGS OF THE ACADEMY OF [PaRT III 



Corolla violet-white, with many fine violet lines within throat 

 on anterior side. Flowering from early May to early June. 



Sandy or gravelly loam (frequently calcareous), on bluffs, low 

 hills or prairies, western Oklahoma and northwestern Texas; 

 chiefly Upper Sonoran Zone (at altitudes above 1,800 feet). Ranges 

 through the High Plains from Manitoba and Montana to northwest- 

 ern Texas. 



Oklahoma. Beaver: Stevens 353 (M, U). (Beckham: observed 

 by Pennell). Harper: Buffalo, Stevens 304 (M, U). Woodward: 

 Woodward, Eggert (M). 



Texas. Armstrong: Gamble's Ranch, E. J. Palmer 13906 (M). 

 Garza: Post, Pennell 10530 (A, C, H, J, K, L, M, S, T, U, Y). 

 Potter: Ady, Pennell 10549 (A, 0, T Y), Amarillo. Randall: 

 Canyon, Pennell 10545 (C, H, M, P, T, U, Y). 



7. Penstemon guadalupensis Heller. 



Penstemon (juadalupcnsis Heller, in Contrib. Herb. Franklin & Marshall 

 Coll. 1:92. pi. 7. 1895. "Very plentiful in dry, stony ground along the 

 Guadalupe and Town Creek [near Kerrville, Texas], altitude 1600-1650 

 feet, April 19, [1894, A. A. Heller] 1609." Isotype seen in herbarium of 

 Academy of Natural Sciences, etc. 



"Corolla white or sometimes faintly tinged with purple." Flow- 

 ering in April and May. 



Sandy, gravelly or rocky open loam or clay, probably calcareous, 

 Edwards Plateau, Concho and Lampasas counties; Lower Sonoran 

 Zone (at altitudes from 1,300 to 2,200 feet). From Howard and 

 Comanche to Kerr Counties, central Texas. 



Texas. Brown: , Reverchon 698 (M, U). Comanche: 



Comanche, Eggert (M). Gillespie: Fredericksburg, Bray 291 (T, 

 U); Pedernales. Howard: Big Spring, Eggert. (M). Kerr: Kerr- 

 ville, Heller 1609 (A, M, U, Y). Nolan: Sweetwater, E. J. Palmer 

 13735 (M). 



8. Penstemon triflorus Heller. 



Penstemon triflorus Heller, in Contrib. Herb. Franklin and Marshall Coll. 

 1: 92. pi. 8. 1895. "Found only along the smnmit of one hill northeast of 

 Kerrville [Texas], altitude 2000 feet . . . April 26 [1894], [A. A. 

 Heller] (1654)." Isotypes seen in the herbaria of the Academy of Natural 

 Scigucgs Gtc 



Penstemon' helleri Small, in Bull. Torr. Bot. Club 25: 471. 1898. "These 

 specimens [Heller 16i0] form the type . . . The original specimens 

 are from Kerrville, Kerry County, Texas, collected in April and June, 

 1894." Type collected April 19, 1894, seen in the Herbarium of Columbia 

 University at ihe New York Botanical Garden. 



Plants very variable, apparently tending to two types, which are 



