STANDLEY TREES AND SHRUBS OF MEXICO 1553 



Shrubby; stem strigillose; petioles 6 to 10 mm. long; blades lanceolate, 6 to 

 10 cm. long, 1 to 2 cm. wide, long-acuminate, acutely cuneate at base, serrulate, 

 rough above, antrorse-hispid and hispidulous beneath; heads in cymes or cymose 

 panicles; pedicels usually about 1.8 cm. long; involucre 5 to 6 mm. high, all but 

 the outermost phyllaries oval, with broadly rounded tips. 



21. Perymenium microcephalum Schultz Bip.; Klatt, Leopoldina 23: 143 



1887. 



Oaxaca; type from Santa Talea. 



Shrubby, finely strigillose; petioles of the upper leaves 4 to 8 mm. long; blades 

 of the upper leaves ovate-lanceolate or ovate, 3 cm. long or less, half as wide, 

 serrate, acute or acuminate, rounded at base; heads numerous, about 1.2 cm. 

 wide; involucre 5 mm. high, the phyllaries obtuse, the inner with scarious yel- 

 lowish tips. 



22. Perymenium gracile Hemsl. Biol. Centr. Amer. Bot. 2: 181. 1881. 

 Known only from the type locality, San Crist6bal, Orizaba, Veracruz. 

 Strigillose; petioles up to 12 mm. long; blades lance-ovate, up to 10 cm. long, 



very acute, serrulate, scabrid-strigillose; heads small, few-flowered, numerous in 

 leafy panicles; involucre 4 mm. high, the phyllaries obtuse. (Description 

 compiled.) 



23. Perymenium chalarolepis Robins. & Greenm. Proc. Amer. Acad. 34: 525. 

 1899. 



Known only from the type locality, mountains of Chiapas. 



Shrub; branches strigillose; petioles 6 to 9 mm. long; blades lanceolate, 4 to 

 6 cm. long, 1 to 1.5 cm. wide, acuminate, sharply serrate, scabrous on both 

 sides; heads small, borne in numerous 5-headed terminal cymes; phyllaries 

 ovate, acuminate, spreading-tipped. (Description compiled.) 



24. Perymenium ghiesbreghtii Robins. & Greenm. Proc. Amer. Acad. 34: 

 525. 1899. 



Chiapas. 



Shrub 1 to 2 meters high; branches strigillose, glabrate; petioles 5 to 12 mm. 

 long; blades lance-oblong, 6 to 11 cm. long, 1.5 to 3 cm. wide, acuminate, cuneate 

 at base, serrate, smoothish above, appressed-hirsutulous beneath; heads in small 

 close cymes; involucre about 5 mm. high, the phyllaries ovate, acuminate, with 

 spreading tips. 



25. Perymenium croceum Robins. & Greenm. Proc. Amer. Acad. 34: 527. 

 1899. 



Durango. 



Shrub; branches strigillose; petioles about 5 mm. long; blades lanceolate or 

 iance-oblong, 5 to 9 cm. long, 1.3 to 1.8 cm. wide, acuminate, cuneate at base, 

 serrate, green and rough above, densely and subcanescently strigillose beneath; 

 heads in cymes of 3 to 5, short-pediceled; involucre 5 to 6 mm. high, the phyl- 

 laries obtuse or the outer acutish, appressed. 



26. Perymenium discolor Schrad. "Ind. Sem. Hort. Gott. 1830;" Linnaea 6: 

 Litt.-Ber. 73. 1831. 



Oaxaca. 



Shrub up to 5 meters high; branches strigose or strigillose; leaves short- 

 pet ioled, lanceolate, 2 to 6.5 cm. long, 5 to 14 mm. wide, attenuate, acutely 

 cuneate at base, green, scabrous, impressed-veined and somewhat rugose above, 

 beneath densely and canescently subtomentose-hispidulous; heads in rounded 

 panicles; involucre 4 mm. high, the phyllaries obtuse or rounded. 



27. Perymenium pellitum Klatt, Leopoldina 23: 143. 1887. 

 Veracruz and Oaxaca; type from Yavesia, Oaxaca. 



Similar to P. discolor; leaves nigrescent in drying; heads usually in 3's, on 

 pedicels 2 to 6 cm. long. 



