Amorphophallus Blume ex Decne.

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

Diagnostic

Seasonally dormant; petiole long, terete, variously spotted or patterned; leaf blade dracontioid, leaf solitary in each growth period; ultimate leaf lobes usually oblong-elliptic, acuminate, with primary lateral veins forming regular submarginal collective vein on each side. Differs from Pseudodracontium in having a 1-4 locular ovary, a terminal appendix which is smooth, rugose, or rarely verrucose or staminodial but not stipitate ( Pseudodracontium always has a 1-locular ovary and a staminodial terminal appendix which is separated from the male zone by a naked axial region).

Distribution

Trop. & S. Africa to Pacific

General Description

HABIT : seasonally dormant (sometimes irregularly so) or rarely semi-evergreen herbs, often large, sometimes gigantic, tuber usually depressed-globose, sometimes irregularly ± elongate-cylindric, napiform or carrot-shaped, rarely rhizomatous or stoloniferous. LEAVES : usually solitary (rarely 2-3) in adult plants, sometimes 2-3 in seedlings. PETIOLE : long, usually smooth, rarely verrucose to asperate, sometimes very thick, usually conspicuously spotted and marked in a variety of patterns, sheath very short. BLADE : trisect, primary divisions pinnatisect, bipinnatisect or dichotomously further divided, tubercles rarely present at junction of divisions, secondary and tertiary divisions ± regularly pinnatifid to pinnatisect, ultimate lobes oblong-elliptic to linear, acuminate, decurrent, rarely petiolulate; primary lateral veins of ultimate lobes pinnate, forming distinct submarginal collective vein, higher order venation reticulate. INFLORESCENCE : always solitary, preceded by cataphylls, usually flowering without leaves, rarely with the leaves. PEDUNCLE : very short to long, similar to petiole. SPATHE : variously coloured, marcescent and finally deciduous, boat-shaped and not or hardly convolute, or clearly differentiated into tube and blade, sometimes constricted between them; tube convolute, rarely connate ( A. pusillus , A. elliotii), campanulate to cylindric or ventricose, inner surface smooth, longitudinally ribbed, near base verruculose, scabrate or densely covered with scale- or hair-like processes or smooth; blade erect to spreading, smooth, ribbed or variously undulate or frilled at margins. SPADIX : shorter or much longer than spathe; female zone shorter, equalling or longer than male zone; male zone cylindric, ellipsoid, conoid or obconoid, usually contiguous with female, sometimes separated by a sterile zone which may be naked, or bear prismatic, subglobose or hair-like sterile flowers; terminal appendix usually present, rarely absent or reduced to stub, erect, sometimes horizontal, rarely pendent, very variable in shape, usually ± conoid or cylindric, rarely ± globose, sometimes ± stipitate or basally narrowed, usually smooth or bearing staminode-like structures near base or entirely covered with staminodes, sometimes corrugate or densely to sparsely hirsute, or grossly and irregularly crumpled. FLOWERS : unisexual, perigone absent. MALE FLOWER : 1-6-androus, stamens free or sometimes connate in basal flowers or throughout male zone, short, filaments absent or distinct, connective fairly thick, sometimes projecting beyond thecae, thecae obovoid or oblong, opposite, dehiscing apically by an apical (rarely lateral) pore or transverse slit. POLLEN : extruded in strands, inaperturate, mostly ellipsoid to ellipsoid-oblong, occasionally spherical or subsphaeroidal, medium-sized to large (mean 53 µm., range 34-82 µm.), exine striate, striate-reticulate, psilate, punctate-foveolate, verrucate, or spinose. FEMALE FLOWER : gynoecia usually crowded, sometimes ± distant, ovary subglobose to ovoid or obovoid, 1-4-locular, ovules 1 per locule, anatropous, funicle very short to distinct, erect, placenta axile to basal, style absent, short or very long, conoid to cylindric, stigma variably shaped, entire and subglobose or 2-4-lobed, stellate or rarely punctiform, sometimes large and brightly coloured. BERRY : sometimes very large, 1 to few-seeded, orange to red, rarely blue or white, infructescence ± cylindric. SEED : ellipsoid, testa smooth, thin, embryo large, somewhat green superficially, endosperm absent.

Habitat

Tropical humid forest, seasonal forest, open woodlands; geophytes, sometimes in humus deposits on rocks (limestone), also in waste places or areas of human habitation (e.g. A. paeoniifolius).

Araceae, S.J. Mayo. Flora of Tropical East Africa. 1985

Morphology General Habit

Medium-sized to very large acaulescent herbs, seasonally dying back and dormant; stem a usually subglobose tuber

Morphology Leaves

Leaf normally solitary subtended by several basal cataphylls; petiole erect, cylindric, not pulvinate apically, usually smooth, rarely verrucose (A. paeoniifolius), often conspicuously spotted; blade widely spreading, in outline forming a shallow inverted cone, tripartite, each major segment highly divided subpinnately or ± irregularly; ultimate lobes linear to broadly elliptic or ovate, with acuminate tips and broadly decurrent bases; venation of the ultimate lobes penniform, forming inframarginal veins on each side

Morphology Reproductive morphology Inflorescences

Spadix with basal pistillate portion contiguous with central staminate portion or separated by a short naked interstice, apical portion a variously shaped, sterile, ± smooth (rarely rugose or staminodial), terminal appendix, spongy fibrous within Spathe usually with convolute basal portion forming cylindric to bowl-shaped tube, upper portion usually ± expanded, much broader, often with undulate margins Inflorescence normally produced before (more rarely with) appearance of leaves; peduncle normally shorter than petiole

Morphology Reproductive morphology Flowers

Flowers unisexual, without perigon

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens usually densely congested, in groups of up to 6 (rarely more), sometimes connate basally; anthers usually sessile, more rarely with distinct filaments, dehiscing by apical pores (rarely by transverse slits); connective usually thick

Morphology Reproductive morphology Flowers Gynoecium Pistil

Pistils usually densely congested, sometimes ± distant; ovary 1–4-locular; ovules 1 per locule on basal to axile placentas; style often elongated, sometimes lacking; stigma subglobose or variously lobed, often brightly coloured

Morphology Reproductive morphology Fruits

Berries borne in ± cylindrical infructescence, 1–several-seeded

Morphology Reproductive morphology Seeds

Seeds smooth, lacking endosperm.

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

Distribution

Indo-China.

General Description

HABIT : seasonally dormant herbs, tuber depressed-globose, napiform or irregularly elongate. LEAVES : often more than 1. PETIOLE : long, usually mottled or otherwise variegated, sheath very short and inconspicuous. BLADE : trisect with 3 ± equal primary divisions, anterior division sometimes smaller than posterior divisions, primary divisions mostly pinnatisect or partly bipinnatisect, ultimate lobes decurrent, sessile or shortly petiolulate, narrowly elliptic, acuminate; primary lateral veins of ultimate lobes pinnate, forming submarginal collective vein, 1 marginal vein also present, higher order venation reticulate. INFLORESCENCE : solitary, usually appearing with leaves. PEDUNCLE : long, longer, shorter or subequal to petiole, similar in appearance to petiole. SPATHE : erect, boat-shaped, convolute basally, slightly fornicate, not constricted, green. SPADIX : shorter to subequal to spathe, female zone shorter than male, densely flowered, male zone laxly flowered, contiguous with female zone, terminal appendix usually shorter than male zone, with naked basal stipe, ± conic, covered with sterile male flowers. FLOWERS : unisexual, perigone absent. MALE FLOWER : 3-6-androus, flowers distinct, ± distant, filaments relatively long, connate to ± free, thecae subglobose, dehiscing by short slit. POLLEN : inaperturate, ellipsoid to oblong, medium-sized (mean 48 µm.), exine narrowly striate. STERILE MALE FLOWERS : composed of clavate, irregularly, ± connate staminodes, not forming distinct floral groups. FEMALE FLOWER : ovary ovoid to subglobose, 1-locular, ovule 1, anatropous, funicle short, placenta basal, style shortly attenuate, stigma discoid-subcapitate. BERRY : ellipsoid, with stigma remnant persisting, 1-seeded. SEED : ellipsoid, testa smooth, brown, raphe conspicuous, embryo large, ellipsoid, somewhat truncate at each end, endosperm absent.

Habitat

Tropical humid and deciduous forest, bamboo forest; geophytes, on forest floor.

Diagnostic

Seasonally-dormant, tuberous geophytes; leaves one to few; leaf blade dracontioid, ultimate lobes with submarginal collective vein, fine venation reticulate; spathe boat-shaped; spadix with terminal appendix composed of staminodes; flowers unisexual, perigone absent; male flowers laxly arranged. Differs from Amorphophallus in having constantly 1-locular ovary and spadix appendix separated from male zone by short naked axis.