810 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



4. Penstemon bridgesii A. Grav, Amer. Acad. Arts and Sci. Proc. 7: 



379. 1868. 

 Kaibab Plateau (Coconino County), south to the Sierra Ancha 

 (Gila County), westward to Mohave and Yavapai Counties, 4,500 to 

 7,500 feet, occasional in the mountains among pinyons and yellow 

 pine, May to September. Southwestern Colorado and western New 

 Mexico to California. 



5. Penstemon barbatus (Cav.) Roth, Cat, Bot, 3: 49. 1806. 



Chelone barbata Cav., Icon. PI. 3: 22. 1794. 

 Penstemon barbatus var. puberulus A. Gray in Torr., U. S. and 

 Mex. Bound. Bot. 114. 1859. 



Kaibab Plateau (Coconino County), southward to the Mexican 

 border, 4,000 to 10,000 feet, common in the mountains in coniferous 

 or in oak woods, June to September. Southern Colorado and Utah 

 to the central highlands of Mexico. 



The typical form, which is the prevalent one in Arizona, has the 

 lower lip of the corolla bearded. The form with a glabrous lower lip, 

 subsp. torreyi (Benth.) Keck (P. torreyi Benth.), is much less frequent 

 than in Colorado and New Mexico. In northern Apache County one 

 occasionally finds subsp. trichander (A. Gray) Keck (P. barbatus var. 

 trichander A. Gray, P. trichander Rydb.), which differs only in having 

 villous anthers. The species as a whole is variable as to the presence 

 or absence of puberulence on the herbage, all gradations being found 

 at random. Therefore var. puberulus A. Gray, founded on a collec- 

 tion from Guadalupe Canyon, Cochise County (Thurber in 1851), is not 

 retained. 



6. Penstemon eatoni A. Gray, Amer. Acad. Arts and Sci. Proc, 8: 



395. 1872. 



Northern Arizona southward to Gila and northern Pinal Counties, 

 2,000 to 7,000 feet, common on mesas, in fields, and at roadsides, 

 sandy or clay soils, March to June. Southwestern Colorado to central 

 Arizona and California. 



Typical P. eatoni, glabrous throughout, is present only in the north- 

 ernmost tier of counties but is abundant in Utah. The 2 more abun- 

 dant forms in Arizona are marked by puberulent stems and leaves. 

 One of these, subsp. undosus (M. E. Jones) Keck (P. eatoni var. 

 undosus M. E. Jones, P. coccinatus Rydb., type from the Grand Can- 

 yon, MacDougal 173), in which the stamens are included within the 

 corolla or barely exserted, is frequent in southern Utah and northern 

 Arizona, occasional in Gila and Pinal Counties. Southward, par- 

 ticularly in Gila and Pinal Counties, the prevailing form is subsp. 

 exsertus (A. Nels.) Keck (P. exsertus A. Nels., type from along Salt 

 River, Nelson 10624, P. am plus A. Nels., type from Oak Creek Can- 

 yon, near Sedona, A. and R. Nelson 2075), in which the stamens are 

 long-exserted. A hybrid between P. eatoni subsp. exsertus and P. 

 palmeri subsp. typicus, collected in Oak Creek Canyon, near Sedona 

 (A. and R. Nelson 2076), has been named P. mirus A. Nels. 



7. Penstemon subulatus M. E. Jones, Contrib. West. Bot. 12: 63. 



1908. 

 Central Mohave County and Yavapai County to Graham, Pinal, 

 and Maricopa Counties, 1,700 to 4,500 feet, stony hillsides, canyons, 



