Robust, single-stemmed perennial 1-3 m, generally ±pubescent or even tomentose; lvs once ternate, with broad, petiolulate, coarsely toothed and palmately lobed lfls mostly 1-3(-4) dm long and wide, the lateral ones mostly narrower than the central and often asymmetrical; terminal umbel commonly 1-2 dm wide at anthesis, with mostly 15-30 rays; bracts 5-10, narrow, deciduous; fr on pedicels 8-20 mm, obovate to obcordate, 7-12 mm, often pubescent; 2n=22. Rich damp soil; Lab. to Alas. and Siberia, s. to Ga. and Ariz. June, July. (H. sphondylium ssp. montanum, as to Amer. plants; H. maximum)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
General: Perennial, 100-300 cm tall; stems solitary, glabrous to tomentose, especially at the nodes; taproot or cluster of fibrous roots. Leaves: Alternate, compound, ovate to orbicular in outline, 20-50 cm long and nearly as wide, once ternate, with leaflets ovate to orbicular, usually with 3 main lobes that are lobed again, woolly-villous at least below, margins of the ultimate lobes serrate; petioles 10-40 cm long or absent on upper leaves, bases dilated, sheathing. Flowers: Inflorescence of 1 to several compound umbels arising from decumbent or ascending scapes 4-20 cm long, with 5- 22 unequal rays, 0.2-9.5 cm long; phyllaries absent; pedicels 1-10 mm long, subtended by 4-8 bractlets, 2-5 mm long, the base distinct or united, apex acute to acuminate, margins entire; calyx teeth up to 0.5 mm long; petals purple or yellow; carpophore cleft to the base; flowers April-June. Fruits: Schizocarp, obovate to obcordate, 8-12 mm long, 5-9 mm wide, dorsally flattened, wings on lateral ribs 1-1.5 mm wide, dorsal ribs narrow and wingless. Ecology: Streambanks, wet meadows, disturbed areas, roadways; 1400-3000 m (4500-10000 ft); Apache, Coconino, and Navajo counties in Arizona; widespread throughout the U.S. Notes: Cowparsnip can be direct-seeded into restoration treatments at relatively high elevations. It is widely used by northern tribes for a plethora of medical conditions, and many parts of the plant are eaten. Only the Paiute use it in our region, as a poultice of mashed root for rheumatism. The roots are also used to make a salve for sores and wounds, and a decoction of the roots is taken for colds. Editor: Springer et al. 2008
From Flora of Indiana (1940) by Charles C. Deam
An infrequent or rare plant in moist, rich soil along streams, about lakes, and along roadsides.
Indiana Coefficient of Conservatism: C = 6
Wetland Indicator Status: FACW
Diagnostic Traits: stout perennial; leaves ternately compound with downy pubescence on lower surface, leaflets broad; inflorescence rays fewer than 35, fruiting pedicels less than 2 cm long; fruits 8-12 mm long, unwinged.