Araceae
Alocasia (Schott) G.Don
SUMMARY
HABIT : medium-sized to rarely arborescent and gigantic, seasonally dormant to evergreen herbs, stem thick, often hypogeal, sometimes stoloniferous and bulbiferous, epigeal stem usually erect, with clear to milky latex. LEAVES : few to several in terminal crown, sometimes each subtended by a cataphyll. PETIOLE : long, sometimes asperate or glandular, sheath relatively long, sometimes deciduous. BLADE : sometimes pubescent, juvenile blade peltate, at maturity usually sagittate, less often ± hastate or cordate, peltate in some species, margin entire, sinuate or slightly to deeply pinnatifid, posterior lobes ovate or triangular; basal ribs well-developed, glands present in axils of primary lateral veins and midrib, primary lateral veins pinnate, forming submarginal collective vein,1-2 closely adjacent marginal veins also present, secondary and tertiary lateral veins arising from the primaries at a wide angle, then arching strongly towards leaf margin, sometimes forming interprimary veins,higher order venation reticulate. INFLORESCENCE : 2-many in each floral sympodium, appearing with the leaves. PEDUNCLE : usually shorter than petiole. SPATHE : strongly constricted between tube and blade, tube with convolute margins, shorter than blade, ovoid or oblong, persistent and then splitting irregularly in fruit, blade oblong, usually boat-shaped, rarely fornicate, at anthesis at first erect, then reflexing and later usually deciduous; in Xenophya group blade is persistent, erect, convolute, gaping only basally. SPADIX : shorter than spathe, female zone short, conoid-cylindric, separated from male by a much narrower zone of sterile flowers, male zone usually cylindric, appendix conoid to cylindric, surface with irregular, labyrinthine network of fissures. FLOWERS : unisexual, perigone absent. MALE FLOWER : 3-12(-36)-androus, stamens connate into an obpyramidal, subhexagonal, truncate, rarely linear (A. brisbanensis) synandrium, thecae linear-oblong, lateral, dehiscing by apical pore. POLLEN : extruded in strands, inaperturate, spherical to subspheroidal, medium-sized (mean 35 µm., range 31-39 µm.), exine spinose. STERILE MALE FLOWERS : synandrodes shallow, obpyramidal, compressed, truncate. FEMALE FLOWER : ovary ovoid or oblong, 1-locular or partially 3-4-locular at apex, ovules 6-10, orthotropous, hemiorthotropous, hemianatropous or anatropous, funicle short, placenta basal, style short, stigma depressed-capitate, ± distinctly 3-4-lobed. BERRY : generally reddish, ellipsoid or obconic-ellipsoid or subglobose, 1-5-seeded, stigma remnants persistent. SEED : subglobose to ellipsoid, testa thickish, smooth or scabrous, embryo broadly conoid, shortly cylindric or elongate, endosperm copious.