Henderson's Biscuitroot

Lomatium hendersonii Coult. & Rose, Contr. U. S. Nat Herb. 7: 209. 1900.
Peucedanum Hendersonii Cpult. & Rose, Bot. Gaz. 13: 210. 1888. Leptotaenia Leibergi Coult. & Rose. Contr. U. S. Nat. Herb. 7: 202. 1900. Cogswellia Hendersoni M. E. Jones, Contr. W. Bot. 12: 33. 1908. Leptotaenia Hendersoni Math. & Const. Bull. Torrey Club 68: 123. 1941.
Plants short-caulescent, 0.8-2.5 dm. high, from large, shallow, subglobose tubers, glabrous; leaves ovate in general outline, excluding the petioles 4-8 cm. long, ternate, then pinnate or bipinnate, the ultimate divisions linear, acute, 4-10 mm. long; petioles 2-5 cm. long, narrowly sheathing at the base; cauline leaves few, like the basal, the sheaths scarious and broadly dilated; peduncles exceeding the leaves; involucel of a few lanceolate bractlets, shorter than the pedicels; rays 5-6, spreading to ascending, 0.5-3 cm. long, unequal; pedicels 2-7 mm. long, few fertile, the umbellets few-flowered; flowers "deep yellow" (appearing white in dried specimens); fruit oblong-oval, 4-8 mm. long, 3-4 mm. broad, glabrous, the wings much narrower than and homochromous with the body, slightly corky-thickened; oil-tubes minute, solitary in the intervals, usually 2 on the commissure.
Type locality: "On high hilltops, John Day Valley, Oregon," Howell. Distribution: Central to southeastern Oregon {Leach 3695).