Rhodosciadium argutum (Rose) Mathias & Constance

Rhodosciadium argutum (Rose) Math. & Const Bull. Torrey Club 68: 124. 1941.
Deanea arguta Rose, Contr. U. S. Nat. Herb. 10: 128. 1906.
Rather stout, about 6 dm. high, the foliage and inflorescence usually scaberulous; leaves deltoid in general outline, excluding the petioles 13-22 cm. long, 1-2-ternate-pinnate, the leaflets ovate to ovate-lanceolate, acute at the apex, rounded to euneate at the base, distinct or the terminal confluent, rather remote, sessile, 1.5-3.5 cm. long, 1-2 cm. broad, serrate and lobed toward the base, scaberulous on the margins and veins; petioles slender, 10-20 cm. long; inflorescence 2-trifurcate, the peduncles slender, 5-13 cm. long, scaberulous at the summit, the lateral umbels often sterile and occasionally some umbels sessile; involucre wanting; involucel of several linear to filiform bractlets 3-7 mm. long, exceeding the flowers but shorter than the fruit; rays 9-12, spreading-ascending, unequal, 2.5-4.5 cm. long, scaberulous; pedicels 1-4, spreading-ascending, 3-7 mm. long, scaberulous; petals greenish-yellow; fruit oval, rounded at apex and base, 8 mm. long, 6 mm. broad, the dorsal ribs prominent, the lateral wings a little narrower than the body; seed-face slightly concave.
Type locality: Alvarez, San Luis Potosi, Palmer 114. Distribution: Known only from the type locality.