Cyrtosperma Griff.

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

Habitat

Tropical humid forest, swamp forest, open swamps and cultivated areas; helophytes in streams, ponds and other wet places.

Distribution

Malesia to Pacific.

General Description

HABIT : slender to gigantic evergreen herbs, usually solitary, sometimes clump-forming, rhizome thick, condensed, creeping. LEAVES : several. PETIOLE : sometimes very long, aculeate, geniculate apically, sheath short. BLADE : deeply sagittate, hastate-sagittate or ± tripartite (posterior divisions usually larger than anterior), veins sometimes aculeate on lower surface; basal ribs very well-developed, primary lateral veins pinnate, running into marginal vein, higher order venation reticulate, . INFLORESCENCE : 1-2 in each floral sympodium, appearing with the leaves. PEDUNCLE : long, similar to petioles. SPATHE : marcescent, erect, blackish purple to white, convolute or not in lower part, upper part rarely somewhat fornicate, long-acuminate and twisted in some species. SPADIX : sessile or stipitate. FLOWERS : bisexual, perigoniate; tepals 4-6, somewhat thickened at apex, fornicate. STAMENS : 4-6, filaments free, flat and broad, connective slender, thecae oblong-ovate, dehiscing by apical slit. POLLEN : monosulcate, ellipsoid, medium-sized (mean 29 µm., range 28-30 µm.), exine foveolate, apertural exine psilate. GYNOECIUM : 1-locular, ovules 1-many, campylotropous to subamphitropous, placenta basal to parietal, style short or inconspicuous, stigma subhemispheric, exuding droplet at anthesis. BERRY : obovoid, 1-7-seeded, usually red when mature, bearing remnants of stigma (in C. cuspidispathum ripe berries are extruded and dangle on strips of tepal epidermis; A. Hay pers. comm.). SEED : reniform to orbicular to helically twisted, cristate, warty or smooth, embryo curved, endosperm present.

Diagnostic

Medium-sized to gigantic helophytes with thick, condensed, creeping rhizomes; petiole spiny, with spines all up-turned or both straight and up-turned, geniculate apically; leaf blade deeply sagittate to hastate-sagittate or ± tripartite, fine venation reticulate; flowers bisexual, perigoniate. Differs from African Lasimorpha in having petiole spines dispersed or in oblique combs, stamen filaments free, lacking stolons and in its tropical Asian to Oceania range. Differs from Lasia in non-spiny internodes and absence of subdivisions of leaf anterior lobe.