STANDLEY TREEI3 AND SHRUBS OF MEXICO 1629 



denticulate, shallowly cordate to subtruncate at the base, glabrous on both 

 surfaces or occasionally slightly flocculent-tomentulose beneath in the early 

 stages but soon glabrate; heads small, radiate; achenes hirtellous or glabrous. 



26. Senecio robinsonianus Greenm. Monogr. Senecio 1: 26. 1901; Bot. 

 Jahrb. Engler 32: 22. 1902; Trees & Shrubs 1: 19. pi. 10. 1902. 



Shrub 2 to 3 meters high; stems terete, covered with a white, densely matted 

 tomentum; leaves petiolate, ovate-rotund, 15 to 20 cm. long, nearly or quite as 

 broad, palmately 7 to 9-nerved from just above the truncate or shallowly cordate 

 base, denticulate to sin'uately sublobate, hirtellous-pubescent above, densely 

 and persistently lanate-tomentose beneath; inflorescence a terminal panicle; 

 heads radiate, disjiosed in glomerules; achenes glabrous. 



27. Senecio albonervius Greenm. Monogr. Senecio 1: 26. 1901; Bot. Jahrb. 

 Engler 32: 22. 1902; Ann. Mo. Bot. Gard. 1: 275. 1914. 



South Mexico; type from the Valley of Tamascaltepec. 



Arborescent, 2 to 4 meters high; stem at first white-tomentose, later glabrate; 

 leaves petiolate, broad-ovate, 3 to 5 cm. long, nearly or quite as broad, sinuately 

 4 to 11-lobed, remotely callous-denticulate, cordate at the base, at first tomen- 

 tulose on both surfaces, more or less glabrate above except on the midrib and 

 nerves; petiole 3 to 10 cm. long; inflorescence a terminal many-headed panicle; 

 heads radiate; achenes glabrous. 

 27a. Senecio eriophyllus Greenm. Field Mus. Bot. ♦: 282. 1907. 



South Mexico; type from hills near Tula, Oaxaca. 



Shrub; stem in the dried state of a dark gray or blackish wood, covered with a 

 light gray cortex; ultimate branches white floccose-tomentose in the earlv stages, 

 glabrate; leaves petiolate, ovate to ovate-oblong, 6 to 10 cm. long, 5 to 8 cm. 

 broad, sinuate-angulate-lobed, rounded to cordate at base, densely and persis- 

 tently white-tomentose on both surfaces; inflorescence a terminal panicle; heads 

 about 12 mm. high, discoid, 10 to 12-flowered; involucral bracts 8, stramineous, 

 floccose-tomentulose at the base, glabrous toward the apex; achenes glabrous. 



28. Senecio lanicaulis Greenm. Monogr. Senecio 1: 26. 1901; Bot. Jahrb. 

 Engler 32: 22. 1902; Field Mus. Bot. 2: 283. 1907. 



South Mexico; type from Pinabete, Chiapas. 



Shrub; stem above densely lanate-tomentose; leaves petiolate, subrotvmd to 

 reniform, cordate, palmately 7 to 9-nerved, 7 to 25 cm. broad, shallowly sinuate- 

 lobed, unequally mucronate-dentate, at first tomentulose but soon gUabrate 

 above, densely and permanently white-] anate-tomentose beneath; inflorescence 

 terminal, many-headed; heads radiate; ray flowers 6 to 8; disk flowers 12 to 20; 

 achenes glabrous. 



29. Senecio reticulatus DC. Prodr. 6: 431. 1837. 

 Senecio dictyophyllus Benth. PL Hartw. 43. 1840. 

 South Mexico; type from Villalpando, Michoacdn. 



Stems erect, 30 to 60 cm. high, from a ligneous base, glabrous; leaves short- 

 petiolate, orbicular-ovate, 3 to 6 cm. long, nearly or quite as broad, shallowly 

 7 to 13-angulate-iobed, glabrous on both surfaces, paler beneath, strongly 

 reticulate-nerved, callous-denticulate, subtruncate to slightly cordate at the 

 base; inflorescence a terminal, somewhat leafy, few-headed, subcorymbose cyme; 

 heads 1 to 1.5 cm. high, radiate; ray flowers 6 to 8; rays bright yellow; disk 

 flowers numerous; achenes glabrous. 



30. Senecio acerifolius Hemsl. Biol. Centr. Amer. Bot. 2: 235. 1881. 

 South Mexico; type from Oaxaca. 



Base of stem unknown but probably ligneous; upper portion of plant glabrous; 

 leaves petiolate, subrotund, acutely 5-angulate-lobed, 4 to 7 cm. long and broad; 

 inflorescence few-headed; heads 12 to 16 mm. high, radiate; disk flowers 30 to 

 40; achenes glabrous. 



