1550 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM 



Leaves rarely cordate, mostly larger. 



Heads few, borne on long pedicels in the upper axils 

 or in a long-peduncled umbellate cyme; phylla- 

 ries with subsquarrose thick-herbaceous tips. 



5. P. subsquarrosum. 



Heads usually numerous and panicled; phyllaries with 



usually appressed tips. 



Heads usually loosely panicled or cymose, much 



exceeding the leaves; involucre 4 to 7 mm. 



high, not strongly graduate 8. P. rude. 



Heads usually closely cymose-panicled at apex of 

 branches, scarcely or not surpassing the leaves; 

 involucre about 4-seriate, strongly graduate, 

 5 to 8 mm. high 14. P. berlandierii. 



1. Perymenium buphthalmoides DC. Prodr. 5: 609. 1836. 



San Luis Potosi to Jalisco, Michoacan, and Puebla; type from Mexico, without 

 definite localit}-. 



Suffrutescent, usually 30 cm. high or less, many-stemmed, usually ascending, 

 strigose or strigillose; leaves short-petioled, elliptic to oblong, sharply serrate, 

 1 to 7.5 cm. long; heads about 3 cm. wide, long-peduncled, usually solitary; 

 phyllaries 2-seriate, subequal, acute or acuminate. 



2. Perymenium jaliscense Robins. & Greenm. Amer. Journ. Sci. III. 50: 154. 



1895. 



Jalisco; type from Rio Blanco. 



Suffrutescent or "herbaceous," about 45 cm. high, strigose and strigillose; 

 leaves short-petioled, the blades elliptic to oblong, 3 to 5.5 cm. long, mostly 

 refiexed, conduplicate, entire; heads few, cymose at apex of usually elongate 

 peduncles; involucre about 5 mm. high. 



3. Perymenium parvifolium A. Gray, Proc. Amer. Acad. 15: 36. 1879. 

 Chihuahua to Queretaro; type from city of San Luis Potosi. 

 Suffrutescent or truly shrubby, much-branched, strigose and strigillose; stem 



leaves lanceolate, rarely ovate, 2 to 5 cm. long, 1.8 cm. wide or less, serrate; 

 those of the branches usuall\' very small, linear or elliptic and obtuse; heads 2.5 

 cm. wide or usually less; involucre 4 to 5 mm. high, the phyllaries obtuse or 

 sometimes acutish. 



4. Perymenium chihuahuense Blake, Contr. U. S. Nat. Herb. 22: 625. 1924. 

 Known only from the type locality, near city of Chihuahua. 



Shrub, strigose and strigillose, with long erect simple branches; leaves short- 

 petioled, lance-ovate, 2 to 3 cm. long, 7 to 10 mm. wide, reflexed, conduplicate, 

 plicate-crisped on margin; heads small, in terminal clusters of 3 to 5; involucre 

 4 to 5 mm. high, the phyllaries obtuse or the outer acutish, densely cinereous- 

 strigillose and ciliate, practically without herbaceous tips. 



5. Perymenium subsquarrosum Robins. & Greenm. Proc. Amer. Acad. 34: 



524. 1899. 



Zacatecas and Puebla; type from Plateado, Zacatecas. 



Shrubby, up to 2.6 meters high, strigillose and strigose; leaves short-petioled, 

 the blades ovate, acute or acuminate, subcordate to rounded at base, the larger 

 3 to 7 cm. long, 2 to 3.5 cm. wide, very rough on both sides; heads long-peduncled 

 from the upper axils, or in a pedunculate cyme; involucre 5 to 7 cm. high, the 

 phyllaries ovate, with obtuse, subsquarrose, herbaceous tips. 



6. Perymenium subcordatum Blake, Contr. U. S. Nat. Herb. 22: 622. 1924. 

 Known only from the type locality, Tlapancingo, Oaxaca. 



Shrub with flexuous branches, strigose and strigillose; leaves short-petioled, 

 ovate, 1.5 to 3 cm. long, 9 to 17 mm. wide, acute, slightly cordate to broadly 



