Symplocarpus foetidus is a perennial, monocotyledon herb; colonial from a thick rhizome, contractile roots pull plants downward into soil (Flora of North America 1993); all parts with skunk odor when crushed, sap irritating, flesh contains needle-like, insoluble calcium oxalate crystals that are very irritating to any herbivore attempting to eat the plant Kingsbury 1964).
Leaves all basal, from rhizome, stalk 5-57 cm long, base sheathing, blade large, 30-60 cm long, egg-shaped, base lobed, appear as flowering ends in early spring and disappear by mid-late summer.
Flowers small, 4-parted, scattered on a fleshy, rounded spadix (flower spike) 8-12 cm diameter, arising at ground level from the rhizome, spike nearly surrounded by a fleshy bract (spath), spotted or striped with maroon, 8-15 cm tall, egg-shaped, tip sharply pointed and curving inward, decaying as fruit develops; blooms Feb.-Mar. before leaves arise; inflorescence produces heat via a biochemical process and can maintain a temperature of around 25º C despite colder environmental temperatures; heat also serves to emit the characteristic odor consisting of indole and amine and skatole compounds (Thorington 2000). The spadix can respond to environmental temperature changes of less than 1º C (Seymour 2004; Kikukatsu et al. 2004), inflorescence visited by flies, beetles and other insects, this is the most likely mode of pollination (Thorington 2000) one study also indicates pollination by wind (Flora of North America 1993), in any case fertilization rate is very low.
Fruit fleshy, dark purple-green to brown, 4-10 cm, (Flora of North America 1993) with a tile=like surface; pulp with mushroom odor, seeds ca 1 cm wide, embedded in spongy white flesh of spadix, fruit pulp eaten by some mammals (Gargiullo, personal observation), seeds eaten by wood ducks, Pheasant & Grouse (Martin et al. 1951).
Wetland status: OBL.
Frequency in NYC: Frequent.
Origin: Native, also parts of N. Asia.
Habitat: Undisturbed swamps, swamp forests woodland stream corridors, moist to saturated soils, soil pH 4-7.
Notes: Sheathed leaf buds often appear in autumn (Thorington 2000). Leaves emerge in spring well before tree canopy closure.