Description from Flora of China
Panax [unranked] Oplopanax Torrey & A. Gray, Fl. N. Amer. 1: 648. 1840; Echinopanax Decaisne & Planchon ex Harms.
Shrubs, annually dying back, hermaphroditic, armed with numerous prickles. Leaves simple, palmately lobed, margins serrate, stipules united with petiole, sheathing at base. Inflorescence a terminal panicle or raceme of umbels. Pedicels not articulate below ovary. Calyx 5-toothed, 3 teeth spinelike. Petals 5, valvate. Stamens 5. Ovary 2-carpellate; styles 2, free or united below. Fruit a drupe, red-yellow at maturity, to 1.2 mm in diam. Seeds depressed; endosperm uniform.
Three species: E Asia, North America; one species in China.