Rhodosciadium tuberosum (Coult. & Rose) Drude

Rhodosciadium tuberosum Coult. & Rose; Urbina, Cat PI. Mex. 108. 1897.
Deanea tuberosa Coult. & Rose, Bot. Gaz. 20: 373. 1895.
Slender, from a swollen tuberous rootstock, 3-8 dm. high, glabrous throughout or the foliage scaberulous; leaves oblong to ovate-lanceolate in general outline, excluding the petioles 5-20 cm. long, 3-15 cm. broad, pinnately or ternate-pinnately decompound, the ultimate divisions linear, acute, 1-8 mm. long, somewhat scaberulous on the veins or glabrate; petioles very slender, 5-25 cm. long; inflorescence of a solitary umbel terminal on each branch or with some axillary umbels below, the peduncles slender, 5-20 cm. long; involucre wanting, or of a single filiform bract; involucel of several linear bractlets 1-5 mm. long, shorter than the flowers and fruit; rays 2-5, spreading-ascending, very unequal, 1.5-8.5 cm. long; pedicels 1-5, spreadingascending, 1-2 mm. long; petals purple; fruit oval to orbicular, rounded or truncate at the apex, cordate at the base, 7-9 mm. long, 5-7 mm. broad, the dorsal ribs prominent, the lateral wings narrower than or equaling the body; seedface slightly concave.
Type locality: "In low meadows, valley of Toluca," Mexico, Pringle 4295. Distribution: Hidalgo, south to Mexico and the Federal District (Pringle 8618, 8735).