STANDLEY TREES AND SHRUBS OF MEXICO 1639 



acuminate, appressed-pilose beneath; heads loosely panicled; invohicre 12 mm 

 high, the outer phyllaries linear or lanceolate. 



5. Trixis pterocaulis Robins. & Greenm. Proc. Amer. Acad. 40: 8 1904 

 Known only from the type locality, Manzanillo, Colima. 



Much branched; leaves sessile or short-petioled, the blades oval or elliptic- 

 oblong, 3 to 10 cm. long, denticulate, very sparsely pubescent beneath; heads 

 loosely panicled; outer phyllaries elliptic to oval-ovate. 



6. Trixis longifolia D. Don, Trans. Linn. Soc. 16: 191. 1830. 



Pcrdicium longifolium Sess6 & Moc; D. Don, Trans. Linn. Soc. 16: 192. 1838 

 as synonym. ' 



Trixis obvallata Hook. & Arn. Bot. Beechey Voy. 300. pi. 65. 1840. 

 Trixis conferta Benth. PI. Hartw. 289. 1848. 



Sonora to San Luis Potosf and Guerrero; type from Mexico, without definite 

 locality. 



Shrubby, 1 to 1.5 meters high, leafy; leaves lanceolate, 3 to 8 cm. long, acumi- 

 nate, subentire or denticulate, usually conduplicate and falcate, from essentially 

 glabrous to somewhat appressed-villous beneath; heads numerous, crowded, 

 leafy-bracted; involucre 1.5 to 2.5 cm. high. "Hierba del golpe" (Sinaloa); 

 "lobo buase" (Sonora); "rosilla de dos colores." 



The flower heads are sometimes placed in the ears as a remedy for earache. 

 6a. Trixis longifolia sericea Robins. & Greenm. Proc. Amer. Acad. 40: 9. 

 1904. 



ITrixis involucrata D. Don, Tcans. Linn. Soc. 16: 193. 1830. 



Hidalgo and Michoacan; type from Tula, Hidalgo. 



Similar; leaves conduplicate, densely silky-pilose beneath. 



6b. Trixis longifolia platyphylla Robins. & Greenm. Proc. Amer. Acad. 40: 9. 

 1904. 



Guerrero; type from Acapulco. 



Leaves eUiptic to obovate, 5 to 10 cm. long, 1.5 to 4 cm. wide, entire or den- 

 ticulate, more or less densely silky-pubescent beneath. 



7. Trixis oligantha Robins. & Greenm. Proc. Amer. Acad. 40: 9. 1904. 

 Oaxaca; type from Monte Alban. 



Leaves on petioles 1 cm. long or less, lance-elliptic or lanceolate, 3 to 9 cm. 

 long, 1.5 to 2.5 cm. wide, acuminate, denticulate, subsericeausly tomentose- 

 pilose beneath; panicle broad, the heads somewhat crowded, 1.2 to 1.8 cm. 

 high; outer phyllaries lance-elliptic or lanceolate, equaling or sometimes surpass- 

 ing the inner. 



8. Trixis hyposericea S. Wats. Proc. Amer. Acad. 25: 157. 1890. 

 Known only from the type locality, near Guadalajara, Jalisco. 



Slender shrub; leaves short-petioled, the blades narrowly lanceolate or lance- 

 linear, attenuate, 4 to 9.5 cm. long, 6 to 13 mm. wide, green above, silky-pilose 

 beneath; outer phyllaries linear or lanceolate, two-thirds as long as the inner or 

 less. 



9. Trixis pringlei Robins. & Greenm. Proc. Amer. Acad. 40: 10. 1904. 

 Known only from the type locality, Tomellfn Canj'on, Oaxaca. 



Leaves lanceolate, 3 to 7 cm. long, 6 to 12 mm. wide, acuminate, entire, silky- 

 tomentose beneath; involucre glandular-puberulent. (Description compiled.) 



10. Trixis angustifolia DC. Prodr. 7: 69. 1838. 

 Trixis rosmarinifolia Nees, Linnaea 20: 699. 1847. 



Durango to Aguascalientes and San Luis Potosf; type from "Cantoue," San 

 Luis Potosi. 



