HABIT : evergreen, usually aromatic (anise-scented) herbs, stem shortly aerial, more rarely arborescent or hypogeal. LEAVES : several, rarely distichous (H. geniculata, H. disticha). PETIOLE : rarely aculeate or pubescent, rarely geniculate apically (H. disticha), sheath usually less than half as long as petiole. BLADE : lanceolate or elliptic or oblong or subtriangular or cordate to sagittate, rarely peltate, usually glabrous, rarely pubescent on midrib and veins; primary lateral veins pinnate, running into marginal vein, secondary and tertiary lateral veins parallel-pinnate. INFLORESCENCE : 1-6 (or more) in each floral sympodium. PEDUNCLE : shorter than petiole. SPATHE : erect, often becoming green, more rarely white or yellow-green or red, persistent, usually not constricted, ellipsoid to boat-shaped, more rarely constricted between tube and blade and then tube convolute, blade gaping at anthesis and afterwards closing. SPADIX : shorter or subequal to spathe, stipitate or sessile, female zone cylindric, male zone usually entirely fertile, contiguous with and longer than female zone, rarely bearing staminodes basally, or very rarely separated by a ± naked interstice. FLOWERS : unisexual, perigone absent. MALE FLOWER : 2-4-androus, rarely 5-6-androus, very rarely 1-androus (H. monandra), stamens free, truncate apically, filament absent or distinct, connective thick, thecae ovoid, ellipsoid or oblong, opening by longitudinal slit, rarely by transversal slit. POLLEN : extruded in strands, inaperturate, ellipsoid to oblong, small (mean 22 µm., range 12-31 µm.), exine perfectly psilate in most species, rarely obscurely fossulate. STERILE MALE FLOWERS : 2-4-androus, sometimes present at base of fertile male zone, staminodia subprismatic, somewhat rounded apically. FEMALE FLOWER : gynoecium ovoid or oblong or subglobose, usually with single, anterior staminode (rarely 2, very rarely 3), equalling or half as long as ovary, sometimes absent (H. lindenii), ovary 2-4-(-5)-locular, ovules many, hemianatropous, funicle long, placenta axile to pseudoaxile, style shortly narrowed or absent, stigma discoid, subhemispheric, subcapitate or slightly 2-4-lobed. BERRY : obovoid or subglobose or cylindric, locules many-seeded, rarely few-seeded. SEED : ellipsoid or elongate ellipsoid, testa thick, distinctly or only slightly costate, embryo axile, elongate, endosperm copious.
Terrestrial, rarely rheophytic; usually aromatic (anise scented - Neotropics; variously of camphor, mango-skin; ginger, etc. - Asian tropics); petiole always pulvinate ca. 2/3 along length, rarely terminally at insertion of leaf blade - Asian tropics exc. Chamaecladon supergroup; leaf blade simple, lanceolate to sagittate, fine venation parallel-pinnate; flowers unisexual, perigone absent; stamens free. Differs from Furtadoa in male flowers consisting of 2-6 stamens without pistillodes, ovaries incompletely 2-5 locular and placentas parietal and axile. Differs from Philodendron mainly in shoot architecture, and in being always terrestrial, never climbing (but rhizome aften considerably elongated - 'geophilous climbers' - or epiphytic, endothecium with cell wall thickenings, presence (often) of staminodes in female zone and being mostly tropical Asian (except Homalomena sect. Curmeria ).