Syngonium Schott

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

Diagnostic

Evergreen, climbing hemiepiphytes with milky latex, sometimes creeping on the ground in submature growth, internodes long; leaf blade cordate, sagittate or hastate to pedatisect or rarely pinnatifid, usually with submarginal collective vein, fine venation reticulate; flowers unisexual, perigone absent; male flowers connate into truncate synandrium; berries connate into indehiscent syncarp.

Distribution

Mexico to Trop. America.

Habitat

Tropical humid forest and disturbed areas; climbing epiphytes and hemiepiphytes, creeping when juvenile.

General Description

Latex milky. HABIT : root-climbing or shortly creeping, evergreen herbs, internodes short to elongate, green. LEAVES : numerous. PETIOLE : sheath long. BLADE : at maturity cordate, oblong-cordate, lanceolate, sagittate, trifid to trisect, pedatifid to pedatisect, rarely pinnatifid, when juvenile entire, ovate to sagittate or cordate-sagittate or hastate; basal ribs usually well-developed, primary lateral veins pinnate, usually forming a submarginal collective vein, 1-2 distinct marginal veins also present, or sometimes primaries long-arcuate and running into margin (e.g. S. schottianum), secondary laterals ± parallel to primaries, higher order venation reticulate to transverse-reticulate. INFLORESCENCE : 1-8 in each floral sympodium. PEDUNCLE : much shorter than petiole, erect at anthesis, pendent in fruit. SPATHE : strongly constricted between tube and blade, tube convolute, ovoid-ellipsoid, or cylindric or globose, sometimes ventricose, persistent, blade usually cream, boat-shaped to expanded at anthesis, erect to spreading, usually marcescent after anthesis, later deciduous. SPADIX : sessile, much shorter than spathe, female zone cylindric to conoid, separated from male zone by zone of sterile flowers, sterile zone constricted, male zone clavate to cylindric or ellipsoid, longer than female zone, fertile to apex. FLOWERS : unisexual, perigone absent. MALE FLOWER : 3-4-androus, stamens connate, synandrium obpyramidal, truncate to rounded at apex, often deeply lobed, common connective thick, overtopping anthers, thecae linear, dehiscing by apical pore or short slit. POLLEN : extruded in strands, inaperturate, ellipsoid-oblong to spherical or subspheroidal, medium-sized (mean 48 µm., range 34-75 µm.), exine minutely fossulate or verruculate, narrowly rugulate and minutely scabrate, spinose or tuberculate. STERILE MALE FLOWERS : ± prismatic synandrodes. FEMALE FLOWER : gynoecia connate, rarely ± free at anthesis and becoming connate later ( S. steyermarkii) , ovary obovoid or oblong-obovoid, (1-)2(-3)-locular, ovules 1(-2) per locule, anatropous, funicle short, placenta axile near septum base to parietal-basal, stylar region as broad as ovary and ± truncate or very slightly attenuate, stigma discoid or 2-lobed, rarely globose, discoid-capitate or cup-shaped, narrower than ovary. BERRIES : connate, forming ovoid to ellipsoid, usually brown, sometimes white, fleshy syncarp, usually exposed at maturity by opening of persistent orange, yellow, red or violet spathe tube. SEED : ovoid to ellipsoid, rather large, testa smooth, thin, black or dark brown, shiny, embryo large, ellipsoid to subglobose, endosperm absent.