HABIT : small, medium-sized or gigantic, seasonally dormant or evergreen herbs, stem either a hypogeal, subglobose or subcylindric tuber or mostly epigeal, massive. LEAVES : several, rosulate in acaulescent plants, forming terminal crown in arborescent species. PETIOLE : sheath rather long. BLADE : peltate, ovate-cordate to sagittate-cordate, posterior lobes rounded, shortly to almost entirely connate; basal ribs well-developed, primary lateral veins pinnate, forming submarginal collective vein, 1-2 marginal veins also present, secondary and tertiary laterals arising from the primaries at a wide angle, then arching strongly towards leaf margin, higher order venation reticulate. INFLORESCENCE : 1-many in each floral sympodium, appearing with the leaves. PEDUNCLE : much shorter than petiole. SPATHE : constricted between tube and blade, sometimes with a second constriction above male zone of spadix, tube with convolute margins, usually much shorter than blade, ovoid or oblong, persistent, enlarging in fruit and then splitting open irregularly, blade white to yellow, oblong and boat-shaped to narrowly lanceolate, reflexing at anthesis, later deciduous. SPADIX : shorter than spathe, female zone short, separated from male by narrower zone of sterile male flowers, male zone cylindric to fusiform, terminal appendix erect, ± smooth, elongate-conoid to fusiform or subulate, sometimes reduced to small, mucronate stub, rarely absent. FLOWERS : unisexual, perigone absent. MALE FLOWER : 3-6-androus, stamens connate into ± truncate synandrium, thecae lateral, oblong-linear, dehiscing by apical pore. POLLEN : extruded in strands, inaperturate, ellipsoid-oblong or spherical to subspheroidal (C. esculenta), small to medium-sized (mean 25 µm., range 25-26 µm), exine finely striate, coarsely swirling-fossulate or fossulate-spinose. STERILE MALE FLOWERS : synandrodes depressed-obpyramidal, truncate, laterally compressed. FEMALE FLOWER : ovary ovoid or oblong, 1-locular, ovules many, hemiorthotropous, funicles relatively long, placentae 2-5, parietal, style short, narrowed or not, sometimes ± absent, stigma discoid-capitate or weakly lobed. BERRY : greenish to whitish or red (?), obconoid or oblong, stigma remnants persistent, many-seeded. SEED : ovoid to ellipsoid, testa thickish, costate, embryo axile, cylindric, endosperm copious.
Small to gigantic, terrestrial or helophytic geophytes, stem tuberous or aerial; leaves peltate with colocasioid fine venation; spadix with terminal sterile appendix, rarely reduced or absent, male and female zones separated by narrower zone of sterile flowers; flowers unisexual, perigone absent; male flower a more-or-less truncate synandrium. Differs from Alocasia in parietal placentation, numerous ovules and always entire leaf blades.
taro, eddoe; C. esculenta is an important food plant in tropical regions, especially the Pacific.