Prionosciadium linearifolium (S. Wats.) Coult. & J. N. Rose

Prionosciadium linearifolium (S. Wats.) Coult. & Rose, Contr. U. S. Nat. Herb. 3: 308. 1895.
Cicula (?) linearifolia S. Wats. Proc. Am. Acad. 22: 415. 1887.
Plants stout, about 3 m. high, the inflorescence scaberulous, otherwise glabrous; basal leaves deltoid in general outline, excluding the petioles 2-4 dm. long, ternately or ternatepinnately decompound, the ultimate divisions linear, acuminate, 3-17 cm. long, 3-9 mm. broad, sharply serrate, the rachis often narrowly entire-bordered but unwinged; upper cauline leaves opposite, 1-2-ternate, the uppermost whorled, opposite, or alternate, simple with a linear elongate blade and inconspicuous sheath; inflorescence compound-umbellate; peduncles rather stout, 5-13 dm. long, subtended by leaves, puberulent at the summit; involucre of 1-several filiform bracts 6-12 mm. long; involucel of several linear-lanceolate to filiform, puberulent bractlets 3-5 mm. long, longer than the flowers but shorter than the fruit; fertile rays 9-15, spreading-ascending, subequal, 1.5-4 cm. long, those of the lateral umbels often fewer and shorter; fertile pedicels 1-5, 3-5 mm. long; calyx-teeth evident but minute, triangular; flowers purple, the ovary glabrous; fruit oval, rounded at the apex, truncate or slightly retuse at the base, 8-1 1 mm. long, 6-8 mm. broad, less strongly compressed than in the other species, glabrous, the dorsal ribs narrowly winged, the lateral more broadly winged than the dorsal but only about one-half the width of the body, the wings and body homochromous, the wings rather thick; oil-tubes 3-several in the intervals, about 6-8 on the commissure; seed nearly terete in cross section, channeled under the intervals, the face involute.
Type locality: Guadalajara, Jalisco, Palmer 275.
Distribution: Zacatecas to Jalisco and Tamaulipas (Pringle 7298, 8634).

Prionosciadium linearifolium is a plant known from the Mexican states of Puebla and Zacatecas. It is a biennial herb with compound leaves with long linear leaflets.