Lomatium bicolor var. leptocarpum (Nuttall ex Torrey & Gray) M. A. Schlessman

Lomatium leptocarpum (T. & G.) Coult. & Rose, Contr. U. S Nat. Herb. 7: 213. 1900.
Peucedanum triternatum var. leptocarpum T. & G. Fl. N. Am. 1: 626. 1840.
Peucedanum leptocarpum Nutt.; T. & G. Fl. N. Am. 1: 626. as syn. 1840.
Peucedanum bicolor S. Wats. Bot. King's Expl. 129. 1871.
Peucedanum ambiguum var. leptocarpum Coult. & Rose, Rev. N. Am. Umbell. 59. 1888.
Lomatium bicolor Coult. & Rose, Contr. U. S. Nat. Herb. 7: 237. 1900.
Peucedanum bicolor var. gumbonis M. E. Jones, Contr. W. Bot. 10: 55. 1902.
Cogswellia bicolor M. E. Jones, Contr. W. Bot. 12: 33. 1908.
Cogswellia leptocarpa M. E. Jones, Contr. W. Bot. 12: 33. 1908.
Lomatium ambiguum var. leptocarpum Jepson, Madrono 1: 159. 1924.
Plants short-caulescent, 1.5-5.5 dm. high, from elongate, moniliform, tuberous roots, glabrous to scaberulous; leaves broadly obovate in general outline, excluding the petioles 9-14 cm. long, 1-2-ternate, then 2-4-pinnate, the ultimate divisions filiform to linear, 0.5-45 mm. long, 0.1-2 mm. broad, mucronulate; petioles 2.2-7 cm. long, wholly sheathing; peduncles exceeding the leaves; involucel of several linear, acute bractlets, about equaling the flowers; rays 4-15, suberect, strict, 2-12 cm. long, unequal; pedicels 2-7 mm. long, the umbellets 10-16-flowered; flowers yellow; fruit narrowly oblong, 10-15 mm. long, 2-5 mm. broad, the wings less than one-half the width of the body; oil-tubes solitary in the intervals, 2-4 on the commissure.
Type locality: "Plains of the Oregon near the confluence of the Wahlamet" [mouth of the Willamette River]. Oregon, Nultall.
Distribution: Northwestern Colorado to northern Idaho, south to northern Arizona and northeastern California (Cusick 2381, 2414, Constance, Beetle bOwnbey 2738).