STAXDLEY TREES AND SHEUBS CF MEXICO 1609 



Suffruticose, much branched, 20 cm. high or less, the branches finely hirtellous • 

 leaves opposite at least below, acerose-filiform, 1 to 2 cm. long, 5 mm wide or 

 less, often with fascicles in their axils; heads solitary, subsessile, yellow, about 

 1.3 cm. wide; involucre about 6 mm. high, dotted with numerous glands; pappus 

 paleae dissected into 3 to 7 bristles. "Hierba de San Nicolds" (Zacatecas)- 

 "contrayerba." ' 



10. Dyssodia treculii (A. Gray) Robinson, Proc. Amer. Acad. 49: 508. 1913. 

 Hijmenatherum treculii A. Gray, Proc. Amer. Acad. 19: 42. 1883. 

 Thymophylla treculii Small, Fl. Southeast. U. S. 1295. 1903. 



Coahuila. Texas; type from southeastern Texas. 



Suffruticulose (?), branched, about 20 cm. high, glabrous or finely pruinose; 

 leaves opposite below, 1 to 2 cm. long, pinnatisect, the lobes 3 to 6 pairs, linear- 

 fiUform, setose-tipped; heads campanulate, 1.3 to 1.7 cm. wide; calyculus evident, 

 of lanceolate acuminate phyllaries; pappus of 5 short outer paleae and 5 bifid, 

 aristate-tipped, much longer inner paleae. 



11. Dyssodia hartvsregi (A. Gray) Robinson, Proc. Amer. Acad. 49: 507. 1913. 

 Hijmenatherum hartwcgi A. Gray, PI. Wright. 1: 117. 1852. 



Tagetes aristata Klatt, Leopoldina 25: 109. 1889. 



Thymophylla hartwegi Woot. & Standi. Contr. U. S. Nat. Herb. 16: 191. 1913. 



Thymophylla pringlei Rydb. N. Amer. Fl. 34: 177. 1915. 



Chihuahua to Aguascahentes and San Luis Potosi; type from Aguascalientes. 

 Arizona and New Mexico. 



Similar to D. treculii; plant distinctly suffruticulose; heads smaller, 0.8 to 

 1.2 cm. wide. 



12. Dyssodia pentachaeta (DC.) Robinson, Proc. Amer. Acad. 49: 507 



1913. 



Hymenatherum pentachaetum DC. Prodr. 5: 642. 1836. 



Thymophylla puberula Rydb. N. Amer. Fl. 34: 177. 1915. 



Thymophylla canescens Rydb. N. Amer. Fl. 34: 178. 1915. 



Coahuila and Nuevo Le6n, south to Hidalgo and San Luis Potosi; type from 

 Monterrey, Nuevo Le6n. Texas to Arizona. 



Suffruticulose, 8 to 25 cm. high, the numerous branches usually procumbent 

 at base, puberulous to cinereous-pilosulous; leaves crowded, chiefly opposite, 



5 to 25 mm. long, pinnatisect with linear-filiform, setose-tipped divisions; heads 

 campanulate-subglobose, long-peduncled, 1.5 to 2.2 cm. wide; involucre 5 to 



6 mm. high, denseh' puberulent or pilosulous. " Parraleiia, " "limoncillo" 

 {Coahuila). 



The cinereous form, T. canescens, is not specifically distinguishable. 



13. Dyssopia berlandieri (DC.) Blake. 

 Hymenatherum berlandieri DC. Prodr. 5: 642. 1836. 

 Thymophylla gracilis Rydb. N. Amer. Fl. 34: 176. 1915. 

 Thy7nophijlla berlandieri Rydb. N. Amer. Fl. 34: 177. 1915. 

 Thymophylla villosula Rydb. N. Amer. Fl. 34: 177. 1915. 



Coahuila, TamauHpas, and Nuevo Le6n; type collected between Santander 

 and Victoria, Tamauhpas. Texas. 



Very similar to D. pentachaeta except for the involucre, which is glabrous except 

 for the conspicuously ciliate margins of the phyllaries. This species also has a 

 cinereous-pubescent form {T. villosula), which can not be separated specifically. 

 "Manzanilla amarilla." 



14. Dyssodia thurberi (A. Gray) A. Nels. Bot. Gaz. 47: 436. 1909. 

 Hymenatherum thurberi A. Gray, Proc. Amer. Acad. 19: 41. 1883. 

 Dyssodia cupulata A. Nels. Bot. Gaz. 47: 435. 1909. 



Thymophylla thurberi Woot. & Standi. Contr. U. S. Nat. Herb. 16: 191. 1913. 



