Dieffenbachia (Araceae)
HABIT : evergreen herbs, sometimes robust, stems erect to decumbent, sometimes ± rhizomatous, rooting proximally, foliose distally, erect and unbranched distally, internodes distinct, green, smooth, with conspicuous annular leaf scars. LEAVES : numerous. PETIOLE : sheath more than half as long as petiole or reaching blade. BLADE : oblong-ovate, elliptic to oblanceolate, dark to light green or sometimes variegated with white, silver, yellow or various shades of green; midrib thick, sulcate or prominent on upper surface, primary lateral veins pinnate, sometimes only weakly differentiated, running into margin, secondary laterals parallel-pinnate, connected by transverse tertiary veins. INFLORESCENCE : (1-)2-several in each floral sympodium, cataphylls short and usually inconspicuous. PEDUNCLE : shorter than petiole. SPATHE : persistent, slightly or distinctly constricted between tube and blade, green, lower part convolute into a usually rather long, persistent tube which splits longitudinally in fruit, upper part expanded into a short, erect or recurved blade. SPADIX : slightly shorter than spathe, female zone entirely adnate to spathe, enclosed within tube, laxly flowered, separated from male zone by subnaked axis with a few, scattered sterile male flowers with reduced staminodes, rarely fertile zones contiguous (D. humilis), male zone fertile to apex, free, subcylindric, densely flowered, erect. FLOWERS : unisexual, perigone absent. MALE FLOWER : stamens 4-5, connate into a subsessile, rhomboid to hexagonal synandrium, truncate at apex, sulcate laterally, anthers lateral, common connective thick, fleshy, thecae oblong-ellipsoid, dehiscing by short, apical, pore-like slit. POLLEN : extruded in strands, inaperturate, ellipsoid to oblong or nearly spherical, large (mean 79 µm., range 54-99 µm.), exine almost perfectly psilate to obscurely verruculate and/or sparingly punctate-foveolate to densely foveolate, rarely coarsely tuberculate (D. parlatorei). STERILE MALE FLOWERS : composed of a whorl of (3-)4-5(-6), ± flattened, irregularly globose-ellipsoid, sometimes ± connate staminodes. FEMALE FLOWER : staminodes 4-5 in a whorl, white, clavate with rounded apices, spreading to erect, surrounding and longer than gynoecium; ovary stout, subglobose to ovoid, thickwalled, 1-3-locular, locule walls bulging outwards giving ovary distinctly lobed appearance when plurilocular, ovules 1 per locule, anatropous, placenta axile to basal, style inconspicuous, stigma massive, almost as broad to broader than ovary, 2-3-lobed or subhemispheric (when unilocular), usually yellow, saturated with oily secretion at anthesis. BERRY : usually borne in arching infructescence, berries globose to 2-3-furrowed, stigma remnants persistent, 1-3-seeded, scarlet red to orange. SEED : globose to ovoid, testa smooth, green to blackish green, embryo large, endosperm absent.
Evergreen helophytes or terrestrial herbs with erect to decumbent aerial stems, internodes distinct, green; leaf blade simple, ovate to oblanceolate often variegated; spathe tube usually rather elongated, persistent into fruit and then splitting to reveal scarlet or orange berries; female zone of spadix entirely adnate to spathe, laxly flowered; flowers unisexual, perigone absent; male flower a truncate synandrium. Differs from Bognera in having female flowers each with a whorl of 4-5 staminodes and parallel-pinnate fine leaf venation.
Mexico to Trop. America.
Tropical and subtropical humid forests, helophytes, at edges of stream banks, or terrestrial in forest leaf litter.