HABIT : medium-sized, seasonally dormant herbs, tuber depressed-globose, sometimes large. LEAVES : solitary. PETIOLE : sheath very short. BLADE : outline ovate to ovate-cordate, entire or pinnatifid; primary lateral veins pinnate, running into margin, higher order venation reticulate. INFLORESCENCE : usually 1, rarely 2 in each floral sympodium, flowering before leaf. PEDUNCLE : short (S. intermedium) to long (S. orbignyanum), slender. SPATHE : oblong-elliptic, boat-shaped, not constricted, cuspidate, at first convolute basally, then widely gaping at anthesis, green or purple (S. intermedium), entirely persistent. SPADIX : entirely adnate to spathe (S. orbignyanum) or male part free (S. intermedium), slightly shorter than spathe, densely flowered, either female zone basal, contiguous with longer male zone and spadix fertile to apex (S. intermedium, S. orbignyanum), or female and male zones sometimes separated by a zone of mixed male and female flowers (S. orbignyanum). FLOWERS : unisexual, perigone absent. MALE FLOWER : 4-7-androus, stamens either connate into a long-stipitate, apically convex, peltate and shallowly 5-7-lobed (stigmatoid) synandrium with anthers almost pendent from thickened common connective, or filaments connate, anthers free and stigmatoids elongated, overtopping anthers (S. intermedium), thecae linear-oblong and dehiscing by longitudinal slit (S. orbignyanum) or subglobose and dehiscing by apical pore (S. intermedium). POLLEN : inaperturate, ellipsoid-oblong, large (mean 54 µm.), exine nearly psilate or shallowly uneven. FEMALE FLOWER : gynoecium surrounded by whorl of 5-8 terete-clavate, short staminodes, ovary ovoid-ellipsoid, 5-8-locular, ovules 1 per locule, suborthotropous, funicle distinct, placenta axile at base of septum, style elongate-attenuate, stigma stellate, 6-8-lobed, lobes subtriangular. BERRY : subglobose to depressed-globose, 5-8-seeded. SEED : shortly ovoid to ± ellipsoid, testa ± smooth to slightly roughened, embryo elongate, endosperm copious.
Seasonally dormant tuberous geophytes; leaf solitary; leaf blade cordate to pinnatifid, submarginal collective veins absent, fine venation reticulate; spadix entirely adnate to the spathe; flowers unisexual, perigone absent; male flower a stalked synandrium; female flowers surrounded by a whorl of free staminodes. Differs from Spathicarpa in 6-8-locular ovary and pinnatifid leaf blade.