Porophyllum viridiflorum (Kunth) DC.

Porophyllum viridifloram (H. B. K.) DC. Prodr. 5: 648. 1836
KUinia viridiflora H. B. K. Nov. Gen. & Sp. 4: 157. 1820. Porophyllum Undent Schultz-Bip.; Seem. Bet. Voy. Herald 308. 1857.
A shrub, 5-10 dm. high; stem branched, terete, glabrous, brown, striate; leaves alternate; petioles about 1 cm. long; blades oval or obovate, obtuse or rounded at the apex, abruptly contracted at the base, 1.5-4 cm. long, rather firm, reticulate, subentire or undulate on the margins, with few marginal glands; heads 1-4 at the ends of the branches, in subracemose bracteate clusters; peduncles erect, 1-2 cm. long; involucre cylindric, 12-13 mm. high, greenish; bracts 5, linear, obtu.se, with a single median row of linear glands; flowers 15-20; corollas greenish or yellowish-white, nearly 1 cm. long; tube slender, hispidulous, 2-3 times as long as the funnelform throat; lobes lanceolate; achenes 8 mm. long, hispidulous; pappus strawcolored, 7 mm. long; bristles hispidulous.
Type locality: Valla<iolid (Morelia). Michoacan.
DisTRiBUTio.N : Tepic to Oaxaca and Vera Cruz.

Porophyllum nutans Rob. & Greenm. Proc. Am. Acad. 32: 31 1896. Porophyllum Holwayanum Grcenman, Proc. Am. Acad. 40: 48. 1904.
A leafy shrub, with terete brownish branches; leaves mostly opposite; petioles filiform, 5-10 mm. long; blades thin, oval or elliptic, entire or sinuate, rounded but often mucronate at the apex, obtuse or acute at the base, 1.5-5 cm. long, with 4-8 oblong glands close to each margin; heads in sub-racemiform leafy clusters at the ends of the branches; involucre cylindric, about 12 mm. high; bracLs 5, linear, obtuse, green, with 2 rows of linear glands; flowers 15 or more; corollas ochroleucous or greenish-white, 8-9 mm. long; tube slender, about 4 times as long as the turbinate throat; lobes deltoid; achenes 5-7 mm. long, hispidulous; pappus strawcolored, 5-6 mm. long; bristles hispidulous. (P. Holwayanum is a luxuriant form with longer involucre, larger leaves, and sometimes 8-12 glands on each leaf-margin.)
Type locality: Mountains near Lake Chapala, Michoacan.
Distribution: Michoacan, Guerrero, Oaxaca, and Jalisco.