Monstera Adans.

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

Habitat

Tropical moist and humid forest, cloud forest; climbing hemiepiphytes, usually on tree trunks, also on rocks or ground ( M. deliciosa).

General Description

HABIT : evergreen climbing herbs. LEAVES : distichous, juvenile leaves sometimes of shingle plant form, rarely variegated. PETIOLE : geniculate apically, sheath usually long, persistent or decomposing to fibrous or membranous mass or entirely deciduous. BLADE : entire, oblique, oblong to ovate-elliptic, often conspicuously and elaborately perforated, more rarely deeply pinnatifid; primary lateral veins pinnate, running into marginal vein, rarely forming an irregular submarginal collective vein ( M. obliqua), secondary laterals often parallel-pinnate, sometimes reticulated (e.g. M. dubia), higher order venation reticulate. INFLORESCENCE : 1-several in each floral sympodium. PEDUNCLE : shorter than petiole. SPATHE : ovate or oblong-ovate, cuspidate, boat-shaped and somewhat convolute basally, white to rose-coloured within, remaining open after anthesis, caducous. SPADIX : sessile, subcylindric, somewhat shorter than spathe. FLOWERS : bisexual, perigone absent, lowermost flowers usually sterile. STAMENS : 4, filaments flattened, connective slender, thecae oblong-ellipsoid, dehiscing by longitudinal slit. POLLEN : fully zonate, hamburger-shaped, medium-sized (mean 48 µm, range 40-52 µm), exine densely foveolate to subreticulate, sparsely and shallowly foveolate or psilate, apertural exine verrucate or rugulate. STERILE FLOWERS : with 4 minute, conic staminodia, pistillode 2-locular, prismatic, lacking ovules. GYNOECIUM : obovoid to ellipsoid, prismatic, ovary 2-locular, ovules 2 per locule, anatropous, funicle short, placenta axile at base of septum; stylar region often massive, broader than ovary, apex truncate to shortly attenuate, stigma oblong-elliptic to linear (in the sense of the spadix axis). BERRY : 1-3-seeded, shedding prismatic stylar region at maturity, pulpy within. SEED : obovoid to ellipsoid, compressed, testa smooth, embryo large, endosperm absent.

Distribution

Mexico to Trop. America.

Diagnostic

Climbing hemiepiphytes with trichosclereids abundant in all tissues; petiole geniculate apically, sheath long, persistent to deciduous; leaves distichous; leaf blade with the two sides usually unequal, fine venation from parallel-pinnate to reticulate; spathe deciduous after flowering; flowers bisexual, perigone absent; ovaries 2-locular. Differs from from Stenospermation and Rhodospatha in more diverse leaf shape, usually perforated or pinnatifid or sometimes both, seeds globose to oblong, 6-22 mm long, endosperm absent and 2 ovules per locule.