Porophyllum punctatum (Mill.) Blake

Porophyllum ervendbergii A. Gray, Proc. Am. Acad. IQ: 35
1883.
A slender shrub, 5 dm. high or more, with terete, brown branches; leaves opposite; petioles slender, about 1 cm. long; blades elliptic, 2-3 cm. long, obtuse at the apex, acute at the base, sinuate, with 2-4 marginal glands on each side, 1 terminal one, and a few scattered over the surface; heads cymose, erect, 10-15-flowered; peduncles 2-3 cm. long, ascending-spreading; involucre cylindric, 1 1-12 mm. high, 3 mm. broad; bracts 5, narrowly linear, acuminate; glands few, linear, in 2 irregular rows; corollas pale with dark streaks, puberulent, 8 mm. long; tube much longer than the funnelform throat; achenes 6.5 mm. long, hispidulous; pappus tawny, 6 mm. long; bristles hirsutulous.
Type locality: Wartenberg, Tamaulipas.
Distrlbution: Tamaulipas; Yucatan (?).

Porophyllum jorullense (H. B. K.) Cass. Diet. Sei. Nat. 43: 57 1826.
KUinia jorullensis H. B. K. Nov. Gen. & Sp. 4: 156. 1820.
A branched shrub, with spreading terete brownish branches; leaves opposite or some of them alternate; petioles slender, about 1 cm. long; blades elliptic or oblong, rounded at the apex, abruptly acute at the base, 1-2.5 cm. long, repand, membranous, with 1 or 2 marginal glands on each side and a single terminal one, or sometimes glandless; heads solitary in the forks; peduncles 3-5 cm. long; involucre cylindro-campanulate, 10—12 mm. high; bracts 5, linear, acute, glabrous, green, with 2 rows of linear glands; flowers 25-30; corollas puberulent, about 1 cm. long, cream-colored; tube slender, many times as long as the funnelform throat; achenes 7 mm. long, hispidulous; pappus straw-colored, 6 mm. long; bristles scabrous.
Type locality; On the eastern declivities of the volcano JoruUo. Distribution: Jalisco to Sinaloa.

Porophyllum nummularium DC. Prodr. 5 : 649. 1836
A shrub, with long terete glabrous brownish branches; leaves mostly opposite; petioles about 1 cm. long; blades oval or rarely broadly elliptic, 1.5-3.5 cm. long, 1-2 cm. wide, sinuate, not very thin, glabrous; glands elliptic, 3-5 along each margin, one at the apex and a few scattered over the surface; heads cymose, with the peduncles more or less spreading in age; involucre at first cylindric, 10-14 mm. high; bracts linear, acute, with two rows of glands; corollas cream-colored, about 1 cm. long; tube slender, pubescent, several times as long as the funnelform throat; lobes linear-lanceolate, puberulent; achenes 6 mm. long, hispidulous; pappus straw-colored, 7 mm. long; bristles hispidulous.
Type locality: Tehuantepcc, Oaxaca.
Distribution: Michoacan to Yucatan and Guatemala.

Porophyllum divaricatum Rydberg, sp. nov
A divaricately branched shrub, with terete, glabrous, brown branches; leaves opposite; petioles about 5 mm long; blades rather thick, 1-2 cm. long, elliptic or rarely oval, glabrous, obtuse at the apex, abruptly acute at the base, with 1 or 2 glands along each margin and a single one at the apex; heads cymose-corymbose; peduncles spreading, 1-3 cm. long; involucre cylindric-campanulate, about 1 cm. high; bracts 5, linear, acute, greenish, with 2 rows of linear glands; corollas nearly white with darker veins, 9 mm. long; tube slender, puberulent, several times as long as the narrowly funnelform throat; achenes 6 mm. long, hispidulous; pappus 6-7 mm. long, straw-colored or at first tinged with pink; bristles scabrous.
Type collected near Mazatlan, Sinaloa. 1899, Goldman 386 (herb. N. Y. Bot. Gard.).
Distribution: Sinaloa to Vera Cruz (?).

Porophyllum palmeri Rose, Contr. U. S. Nat. Herb. 1: 338 1895.
A glabrous shrub, 1 m. or more high, divaricately branched, with reddish glabrous twigs; leaves opposite; petioles slender, 5-10 mm. long; blades firm, lanceolate or oblong, acute or obtuse at the apex, acute at the base, 1-4 cm. long, with 2-4 linear glands along each margin; heads cymose-corymbose ; peduncles 1.5-2.5 cm. long; involucre cylindro-campanulate, about 12 mm. high; bracts 5, linear, greenish, acuminate, with 2 rows of linear glands; flowers about 20; corollas nearly white, about 1 cm. long; tube slender, several times as long as the funnelform throat; lobes lanceolate; achenes 7 mm. long, hispidulous, somewhat tapering at the apex; pappus straw-colored, 7 mm. long; bristles scabrous.
Type locality: Colima.
Distribution: Known only from the type locality.

Porophyllum pittieri Rydberg, sp. nov
A slender glabrous shrub; branches slender, purple, striate; leaves opposite; petioles 2-5 mm. long; blades thick, eUiptic, rounded at each end, less than 1 cm. long, usually with a single gland on each margin and one at the apex; heads in small cymes or solitary; peduncles 1-2 cm. long; involucre cylindro-campanulate, 1 cm. high, purplish or pink; bracts 5, linear, acuminate, with 2 rows of linear glands; Howers 15-20; corollas purplish, 8 mm. long; tube pubcrulent, several times as long as the funnclform throat; lobes narrowly lanceolate; achenes 7 mm. long, hispidulous, decidedly tapering above; pappus ochroleucous, slightly tinged with purple at the tips, 7 mm. long; bristles hispidulous.
Type collected at Cucsta de Quililhi, near Punilha, Baja Verapaz, Guatemala, 1905, Pittier 146 (U. S. Nat. Herb.).

Porophyllum oblongum Rydberg, sp. nov
A shrub, with slender, terete, striate, brownish branches; leaves mostly opposite; petioles slender, 1-1.5 cm. long; blades oblong or rarely elliptic, 2-4 cm. long, 0.5-1.5 cm. wide, very thin, sinuate-undulate, with 3-6 marginal glands on each side, 1 terminal one, and a few scattered over the surface; heads cymose; peduncles more or less spreading, 2-4 cm. long; involucre 12-13 mm. high, cylindric, pale; bracts mostly 5, linear, acute, with 2 rows of linear glands; corollas almost white, about I cm. long; tube slender, puberulent, much longer than the funnelform throat; achenes pale, 6 mm. long, hairy; pappus straw-colored, 7 mm. long; bristles scabrous.
Type collected at Culiacan, 1891, Palmer 1807 (herb. N. Y. Bot. Gard.).
Distribution: Sinaloa.

Porophyllum punctatum là một loài thực vật có hoa trong họ Cúc. Loài này được (Mill.) S.F.Blake miêu tả khoa học đầu tiên năm 1917.