STANDLEY TREES AND SHRUBS OF MEXICO 1601 



1. Perityle incana A. Graj-, Proc. Amer. Acad. 11: 78. 1876. 

 Nesothamnus incanus Rydb. N. Amer. Fl. 34: 12. 1914. 



Known only from the type locality, Guadalupe Island, Baja California. 



Shrub 1 meter high, densely and closely white-tomentose throughout; leaf 

 blades 2.5 to 7 cm. long and wide, pinnately cut, the divisions bluntly lobed and 

 toothed; heads about 6 mm. wide, very numerous in a naked pedunculate panicle; 

 aehenes rather densely pubescent and ciliate; pappus of squamellae, without awns. 



2. Perityle spilanthoides (Schultz Bip.) Rydb. N. Amer. Fl. 34: 17. 1914. 

 Galinsogeopsis spilanthoides Schultz Bip. in Seem. Bot. Voy. Herald 307. 1856. 

 Pericome spilanthoides Benth. & Hook.; Hemsl. Biol. Centr. Amer. Bot. 2: 



215. 1881. 



Perityle microcephala A. Gray, Proc. Amer. Acad. 21: 391. 1886. 



Perityle saxosa T. S. Brandeg. Zoe 5: 225. 1905. 



Sinaloa, Chihuahua, and Durango; type from ths Sierra Madre of northwestern 

 Mexico. Arizona. 



Suflfruticulose, lax or decumbent, much branched, up to 40 cm. long, griseous- 

 puberulous; leaf blades 1 to 5 cm. long and wide; heads cymose-panicled; pappus 

 a crown of squamellae and 1 or 2 awns, these shorter than the achene. 



3. Perityle rosei Greenm. Proc. Amer. Acad. 40: 45. 1905. 



Known only from the type locality. Sierra Madre west of Bolanos, Jalisco. 



Suffruticulose, 10 to 20 cm. high, pilosulous; leaf blades deltoid-ovate, 1 to 3 cm. 

 long, 0.5 to 2 cm. wide; pappus a crown of squamellae, and 2 awns about as long 

 as the achene. 



4. Perityle hofmeisteria Rydb N. Amer. Fl. 34: 18. 1914. 



Known only from the type locality, vicinity of City of Durango, Durango. 



Suffruticulose, diffusely branched, about 15 cm. high, finely puberulent; petioles 

 5 to 14 mm. long; leaf blades ovate or rhombic-ovate, 3 to 8 mm. long; heads soli- 

 tary, on peduncles 1 to 3 cm. long; involucre puberulous but green; pappus a 

 crown of squamellae and 2 awns about as long as the achene. 



5. Perityle trichodonta Blake, Proc. Biol. Soc. Washington 37: 60. 1924. 

 Known only from the type locality, Sierra Madre west of Bolanos, Jalisco. 

 Suffruticulose, 10 cm. high, densely griseous-puberulous; petioles about 2 mm. 



long; leaf blades ovate or rhombic-ovate, 3 to 5 mm. long; peduncles 1 cm. long 

 or less; involucre griseous-pilosulous; pappus as in the last species. 



6. Perityle jaliscana A. Gray in S. Wats. Proc. Amer. Acad. 22: 431. 1887. 

 Jalisco; type from Rio Blanco. 



Suffruticulose, loose or procumbent, up to 25 cm. long, puberulent; leaf blades 

 deltoid-ovate, 1 to 1.8 cm. long, coarsely toothed, about equaling the petioles; 

 heads axillary and terminal, discoid; aehenes sometimes 1-carinate on the faces; 

 pappus awns 1 mm. long or less; squamellae very short. 



7. Perityle lineariloba Rydb. N. Amer. Fl. 34: 18. 1914. 

 Known only from the type locality, San Ram6n, Durango. 

 Suffruticulose (?), decumbent, about 30 cm. long, puberulous; leaf blades 



triangular in outline, 2 to 4 cm. long, pinnately 3 to 5-parted with entire or 

 laciniate-lobed divisions, very thin; peduncles 5 to 10 cm. long; rays white, about 

 4 mm. long. 



8. Perityle coronopifolia A. Gray, PI. Wright. 2: 82. 1853. 

 Laphamia coronopifolia Hemsl. Biol. Centr. Amer. Bot. 2: 210. 1881. 

 ILaphamia scopulorum Jones, Contr. West. Bot. 12: 48. 1908. 

 Chihuahua and Sonora. Arizona and New Mexico; type from Copper Mines, 



New Mexico. 



Suffruticulose, many-stemmed, diffusely branched or erect, up to 25 cm. long, 

 puberulous; leaf blades triangular, 3 to 12 mm. long, ternately pinnatisect, the 

 primary divisions usually lobed or toothed; rays white, 3 to 6 mm. long. 



