Prionosciadium acuminatum Robinson ex Coult. & Rose

Prionosciadium acuminatum B. L. Robinson; Coult. & Rose, Proc. Wash. Acad. 1: 149. 1900.
Prionosciadium mexicanum var. acuminatum B. L. Robinson; Urbina, Cat. PI. Mex. 108. 1897.
Plants stout, 1-2 m. high, the inflorescence puberulent, the foliage glabrous to villous; basal leaves ovate in general outline, excluding the petioles 2-4 dm. long, 1-2-ternate to 1-2pinnate, the leaflets ovate to lanceolate, acuminate at the apex, cuneate at the base, 5-12 cm. long, 2-5.6 cm. broad, sharply doubly serrate and often lobed toward the base, the sinuses narrow, confluent by a coarsely serrate, winged rachis; upper cauline leaves opposite, ternate, the sheaths obsolete; inflorescence several times trifurcate or with some irregular branching; the peduncles slender, 2-6.5 cm. long, each subtended by a pair of leaves or occasionally by a solitary leaf; involucre of 1-several filiform bracts 5-20 mm. long; involucel of several filiform bractlets 3-7 mm. long, about equaling the flowers but shorter than the fruit ; fertile rays 3-8, spreading or divaricate, subequal, 1-3 cm. long; fertile pedicels 1-3, 2-6 mm. long; flowers greenish-yellow to purple, the ovary and young fruit hispidulous; fruit ovoid-oblong, rounded or truncate at the apex, retuse at the base, 8-14 mm. long, 7-10 mm. broad, glabrous, the dorsal ribs prominent to narrowly winged, the lateral broadly thin-winged, the wings much broader than the body; oiltubes small, 2-several in the intervals, about 6 on the commissure; seed nearly terete in cross section, channeled under the intervals, the face sulcate.
Type locality: "Barranca near Guadalajara," Jalisco, Pringle 3864.
Distribution: Sinaloa to Michoacan (Pringle 7634, 8635).