STANDLEY TBEES AND SHEUBS OF MEXICO 1539 



57. WEDELIA Jacq. Eniim. PI. Carib. 8. 1760. 

 1. Wedelia acapulcensis H. B. K. Nov. Gen. & Sp. 4: 215. 1820. 



Sinaloa to Guerrero and Oaxaca, and perhaps farther southward; type from 

 Acapulco, Guerrero. 



Suffrutescent, hispidulous and spreading-hirsute; leaves opposite, short- 

 petioled, ovate, 3.5 to 8 cm. long, 1.5 to 4.8 cm. wide, serrate, harsh-pubescent; 

 heads solitary or few at tips of stem and branches, long-peduncled, radiate, yellow, 

 1.5 to 2.2 cm. wide; involucre 2 or 3-seriate, the phyllaries herbaceous above, or 

 the outermost so throughout; rays fertile; achenes obovoid, thickened, sometimes 

 thin-margined but not truly winged; pappus a crown of connate fimbriate squa- 

 mellae and usually 2 awns. 



58. WYETHIA Nutt. Journ. Acad. Phila. 7: 39. ph 5. 1834. 

 1. Wyethia mexicana S. Wats. Proc. Amer. Acad. 25: 154. 1890. 



Known only from the type locality, near Monterrey, Nuevo Le6n. 



Suffrutescent, 1 to 1.6 meters high, spreading-hirsute; leaves alternate, the 

 blades lance-ovate, 6 to 10 cm. long, crenate-dentate, green above, cinereous- 

 subtomentose beneath; heads few, yellow, 3 to 5.5 cm. wide; involucre several- 

 seriate, graduate, the phyllaries lanceolate, pubescent and densely ciliate, squar- 

 rose; rays fertile; achenes subquadrangular, several-ribbed; pappus of 2 short 

 unequal paleaceous awns, connected by a crown of very short connate squamellae. 



59. ASPILIA Thouars, Gen. Nov. Madagasc. 12. 1806. 

 Shrubs or herbs; leaves opposite; heads radiate, rarely discoid, yellow, rarely 

 white or purple, the rays neutral; involucre few-seriate, the phyllaries herbaceous 

 at least at apex; achenes obovoid, plump, wingless; pappus a cup composed of 

 united squamellae, sometimes with awns added. 

 Leaves linear or narrowly linear-lanceolate. 

 Plants tall; heads several or numerous. 



Leaves densely hispid-pilose beneath 1. A. angusta. 



Leaves rather sparsely strigillose or strigose beneath. __2. A. stenophylla. 



Plants low; heads solitary 3. A. rosei. 



Leaves elliptic or oblong to ovate. 

 Rays yellow. 



Leaves elliptic-lanceolate; plant 30 cm. high or less --3. A. rosei. 



Leaves ovate or lance-ovate; plant much taller 4. A. strigosa. 



Rays purple or none. 



Rays purple 5- A. purpurea. 



Rays none 6. A. aggregata. 



1. Aspilia angusta Blake, Contr. U. S. Nat. Herb. 22: 619. 1924. 



Aspilia angustifolia A. Gray in S. Wats. Proc. Amer. Acad. 22: 425. 1887. 

 Not A. angustifolia Oliver & Hiern, 1877. 



Known only from the type locality, Tequila, Jalisco. 



Suffrutescent (?), about 1.5 meters high, densely tuberculate-strigillose or 

 ascending-hispidulous; leaves short-petioled, linear-lanceolate, 4 to 6.5 cm. long, 

 4 to 7 mm. wide, very harsh above, obscurely serrulate; heads numerous, loosely 

 panicled, about 2 cm. wide; phyllaries indurate to middle or above. 



2. Aspilia stenophylla Greenm. Proc. Amer. Acad. 39: 102. 1903. 

 Sierra Madre of Chihuahua; type from Seven Star Mine. 



Suffrutescent (?), about 70 cm. high, finely strigillose; leaves short-petioled, 

 linear-lanceolate or linear, 3.5 to 12 cm. long, 2.5 to 10 mm. wide; heads 1.5 to 

 1.8 cm. wide; outer phyllaries caudate-acuminate. 



