Porophyllum leiocarpum (Urban) Rydb.

Porophyllum leiocarpum (Urban) Rydberg, sp. nov
Porophyllum macrocc phalum leiocarpum Urban, Symb. Ant. 1: 466. 1900.
An erect annual; stem branched above, glabrous, often violet and glaucous, striate; leaves opposite or some alternate; petioles 1-2 cm. long; blades oval, thin, 1-4 cm. long, subentire or sinuate, usually rounded at both ends, with a few oblong glands near the sinuses of the margins and one at the apex; heads solitary at the ends of the branches; peduncles slightly clavate, erect, 4-5 cm. long; involucre at first cylindric, 20-22 mm. high, 5-S mm. broad, in age more turbinate and broader: bracts 5, linear, acute, with 2 rows of linear glands; corollas 10-12 mm. long; tube slender, much longer than the funnelform dark-purple throat; lobes narrowly lanceolate; achenes dark, 10 mm. long, glabrous; pappus about 8 mm. long; bristles 20-80, minutely scabrous.
Type locality: Near Aybonito, Porto Rico.
Distribution: Porto Rico.