This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
A densely prickly shrub, with palmately lobed leaves and racemed or panicled umbels of small greenish-white flowers. Calyx-teeth obsolete; petals 5, valvate; stamens 5; filaments filiform; anthers oblong or ovate; ovary 2-3-celled; styles 2; stigma terminal. Fruit laterally compressed, of 2 carpels. [Greek, prickly Panax.]
A monotypic genus of northwestern North America and northeastern Asia.
Panax horridum J. E. Smith, in Rees' Cyclop. 26: no. 10.
1819. E. horridum Decne. & Planch.; Cooper, Pac. R. R. Rep. 12:
31. 1860. Oplopanax horridum Miq. Ann. Mus. Bot. Lugd. Bat. 1: 116.
1863. Fatsia horrida B. & H.; S. Wats. Bot. Cal. 1: 273. 1876.
Stems erect from a decumbent base, up to 13o high, densely prickly, leafy above; leaves nearly orbicular in outline, 6-20 broad, cordate at the base with a rather narrow sinus, 3-11-lobed, with scattered prickles on both sides and puberulent beneath, the lobes acute, sharply irregularly serrate; inflorescence wooly, terminal, 4'-12' long; peduncles subtended by a narrow laciniate bract; pedicels filiform; stamens about twice as long as the ovate petals; fruit 2"-2 1/2" long, scarlet.
In rocky places, Isle Royale, Lake Superior; Montana to Oregon and Alaska; also in Japan. June.