HABIT : fairly large, seasonally dormant herbs, rhizome thick, erect with thick roots. LEAVES : few. PETIOLE : fairly broad, sulcate, sheath short. BLADE : subcordate- to cordate-ovate; primary lateral veins pinnate, arching towards apex, running into inconspicuous marginal vein, secondary laterals and higher order venation reticulate to transverse-reticulate. INFLORESCENCE : 1-2 in each floral sympodium, appearing before or with leaves. PEDUNCLE : only shortly exserted above ground. SPATHE : thick, boat-shaped or conchiform, lower part convolute, upper part somewhat to widely gaping, apex 2-keeled, rostrate, curving forwards. SPADIX : stipitate, subglobose, hidden within spathe. FLOWERS : bisexual, perigoniate; tepals 4, fornicate, imbricate. STAMENS : 4, filaments flattened, connective slender, thecae oblong, dehiscing by longitudinal slit. POLLEN : monosulcate, ellipsoid, medium-sized (mean 33 µm.), exine reticulate, apertural exine coarsely verrucate. GYNOECIUM : ovary somewhat immersed in spadix axis, 1-locular, ovule 1, orthotropous, funicle very short, placenta apical-parietal, style long-attenuate, stigma punctate-discoid. BERRY : tepals and style persistent to ripe fruiting stage, seed and base of berry immersed in spongy spadix axis, infructescence ± globose. SEED : globose, testa thin, smooth, embryo globose, endosperm very sparse, only a single cell layer thick.
Seasonally dormant geophytes with thick, erect rhizomes; leaf blade subcordate to cordate-ovate, fine venation reticulate to transverse-reticulate; spadix stipitate, subglobose; spathe boat-shaped or hooded, enclosing the spadix; flowers bisexual, periogoniate, with 4 tepals. Differs from Lysichiton in dark, boat-shaped or hooded spathe inserted just below spadix, spadix enclosed within spathe, subglobose with a short stipe.
Temperate damp woodlands, rarely open wetlands, from near sea level to ca. 900m. alt.; usually in shaded sites, frequent near water courses; S. foetidus and S. renifolius flower in early spring before the leaves appear and fruit in the summer of the same year; S. nipponicus flowers after the leaves appear and the fruits ripen in the following spring.