Arophyton (Araceae)
HABIT : seasonally dormant herbs, rhizomatous or tuberous. LEAVES : 1-few. PETIOLE : sheath short. BLADE : cordate, hastate, trifid to trisect or pedatifid, primary lateral veins pinnate, forming submarginal collective vein, secondary laterals sometimes parallel-pinnate, otherwise higher order venation reticulate. INFLORESCENCE : (1-)2-3 in each floral sympodium. PEDUNCLE : subequal or shorter than petiole. SPATHE : not or slightly constricted between tube and blade, tube persistent at maturity or entire spathe marcescent, blade widely spreading, white or cream to greenish within. SPADIX : fertile to apex, or with short appendix, entirely free or female zone partly adnate to spathe, female zone contiguous with male, or separated by synandrodia or a few bisexual flowers. FLOWERS : unisexual, perigone absent. MALE FLOWER : 2-7-androus, stamens connate, synandrium elongate-ellipsoid, often irregularly shaped, shallow, truncate, sometimes with a central slit, common connective broad, thecae marginal, broad-ellipsoid to globular, dehiscing by slit or pore on upper surface. POLLEN : inaperturate, spherical to subspheroidal, medium-sized (mean 32 µm., range 27-36 µm.), exine spinose. FEMALE FLOWER : gynoecium surrounded by cup-like synandrodium, ovary 1-locular, ovule 1, orthotropous, funicle usually short, placenta basal, style short to relatively long and cylindric-conoid, or ± absent, stigma discoid. STERILE FLOWERS : truncate synandrodium with central cavity. BISEXUAL FLOWERS : as for female flowers, but surrounded by synandrium bearing a few scattered thecae. BERRY : ellipsoid to fusiform or clavate, red or green. SEED : ellipsoid to globular, testa thin, smooth, embryo large, globular or ellipsoid, plumule subapical, endosperm absent.
Seasonally dormant geophytes or epiphytes; leaf blade cordate, trifid, trisect or pedatifid, submarginal collective vein present, fine venation transitional between parallel-pinnate and reticulate; spadix sometimes with short sterile terminal appendix; flowers unisexual, perigone absent; synandrium with marginal thecae dehiscing on the upper surface; female flowers surrounded by a cup-like synandrode. Colletogyne differs in the invariably cordate leaf blades, female zone entirely adnate to spathe and synandria composed of a single stamen. Carlephyton differs in the spadix always fertile to the apex, and the thecae either dehiscing on lower surface of synandrium, or with upper part of stamens free.
Madagascar.
Tropical humid, seasonal forest or deciduous forest on limestone; geophytes or epiphytes, litter-filled crevices and holes.