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  1. Family: Araceae Juss.

    1. Xanthosoma Schott

        2. This genus is accepted, and its native range is Mexico to Tropical America.

    [CATE]

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

    Habitat
    Tropical moist and humid forest, subtropical forest; geophytes on forest floor, in wet places, swamps, river banks, seasonally flooded sites, grassy places, plantations, some species are weedy.
    Diagnostic
    Small to gigantic terrestrial, evergreen or seasonally dormant herbs with milky latex, stem tuberous and hypogeal or aerial and erect; leaf blade usually cordate or sagittate to pedatisect, submarginal collective vein present, fine venation reticulate; spathe strongly constricted, tube persistent, blade deciduous after flowering; spadix male and female zones separated by conspicuous zone of sterile flowers, fertile to apex; flowers unisexual, perigone absent; male flower a truncate synandrium. Differs from Chlorospatha in having a subglobose, inflated spathe tube, female zone of spadix free from spathe, styles normally discoid (laterally swollen) and coherent (except Xanthosoma plowmanii ), synandrodes (sterile flowers) between male and female flowers well-developed, ± prismatic.
    Vernacular
    “ cocoyam”, “ tannia"
    Distribution
    Mexico to Trop. America.
    General Description
    Latex milky. HABIT : small to gigantic, sometimes arborescent, evergreen or seasonally dormant herbs, stem either a thick, subcylindric, hypogeal tuber often producing smaller tubers on stoloniferous side branches or often with a distal, epigeal, massive, arborescent upper part, or an entirely hypogeal subglobose tuber, bearing many very small tubercles in some spp. ( X. pubescens , X. viviparum), tuber sometimes yellow within. LEAVES : several, rarely pubescent. PETIOLE : sheath usually rather long. BLADE : cordate, sagittate, hastate, trifid, trisect, pedatifid or pedatisect, rarely linear-lanceolate to ovate with emarginate base, rarely peltate; basal ribs well-developed, often denuded proximally, primary lateral veins pinnate, forming submarginal collective vein, 1 or more distinct marginal veins also present, secondary and tertiary laterals arising from the primaries at a wide angle, forming interprimary collective vein, higher order venation reticulate. INFLORESCENCE : 1 to many in each floral sympodium, always appearing with leaves. PEDUNCLE : usually rather short, rarely long. SPATHE : strongly constricted, tube with convolute margins, ovoid to ellipsoid, usually ventricose, rather thick-walled in large species, persistent, blade boat-shaped-oblong to -oblong-lanceolate, gaping and erect or sometimes reflexed at anthesis, marcescent after anthesis and then deciduous. SPADIX : shorter than spathe, densely flowered, female zone cylindric-conoid, often obliquely inserted onto peduncle, separated from male zone by longer, conoid to attenuate, basally thicker zone of sterile male flowers, male zone cylindric-conoid, longer than female zone, usually fertile to apex, rarely with a few sterile flowers at extreme apex. FLOWERS : unisexual, perigone absent. MALE FLOWER : 4-6-androus, connate into a truncate-obpyramidal, subpentagonal or hexagonal synandrium, anthers lateral, nearly reaching base of synandrium, common connective thick, thecae obversely oblong or tapering basally, dehiscing by subapical pore or short slit. POLLEN : extruded in strands, shed in tetrads, inaperturate, ellipsoid to subspherical, medium-sized (mean 42 µm., range 35-49 µm., tetrads :- mean 76 µm., range 62-97 µm.), exine minutely punctate- or fossulate-verruculate. STERILE MALE FLOWER : composed of obpyramidal truncate, laterally compressed synandrodes, lowermost larger, uppermost narrower and more elongated (in sense of spadix axis). FEMALE FLOWER : ovary ovoid, 2-4-locular, more rarely 1-locular, ovules (12-)20 to very numerous, anatropous or hemianatropous, funicles rather long, placentae usually pseudoaxile, or sometimes parietal or axile basally, style broader than ovary, usually discoid-thickened coherent to weakly connate with those of neighbouring flowers, rarely free and swollen ( X. plowmanii), stigma subhemispheric or 2-4-lobed, yellow, narrower than style. BERRY : cylindric, somewhat furrowed apically, whitish to orange, many-seeded. SEED : ovoid, testa costate, embryo axile, subequal to endosperm, endosperm copious.
    [CATE]
    Use
    X. sagittifolium and its many varieties are important subsistence food plants throughout the humid tropics of the world due to their starch- and protein-rich tuberous stems (see chapter 15).

    Images

    Distribution

    Native to:

    Argentina Northwest, Belize, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, French Guiana, Guatemala, Guyana, Haiti, Honduras, Leeward Is., Mexico Central, Mexico Gulf, Mexico Northwest, Mexico Southeast, Mexico Southwest, Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Suriname, Trinidad-Tobago, Venezuela, Windward Is.

    Introduced into:

    Alabama, Bangladesh, Benin, Borneo, Cayman Is., Christmas I., Cook Is., Easter Is., Gabon, Galápagos, Gilbert Is., Guinea, Guinea-Bissau, Gulf of Guinea Is., Hawaii, Jamaica, Malaya, Niue, Norfolk Is., Society Is., Venezuelan Antilles, Zaïre, Zimbabwe

    Xanthosoma Schott appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    27378.000

    First published in H.W.Schott & S.L.Endlicher, Melet. Bot.: 19 (1832)

    Accepted by

    • Govaerts, R. & Frodin, D.G. (2002). World Checklist and Bibliography of Araceae (and Acoraceae): 1-560. The Board of Trustees of the Royal Botanic Gardens, Kew.

    Literature

    Flora of West Tropical Africa
    • Engl., Pflanzenr. 4, 23 E: 41 (1920).
    • in Schott & Endl., Melet. 1: 19 (1832)
    CATE Araceae
    • Royal Botanic Gardens, Kew 2008. World Checklist of Selected Plant Families.

    Sources

    CATE Araceae
    Haigh, A., Clark, B., Reynolds, L., Mayo, S.J., Croat, T.B., Lay, L., Boyce, P.C., Mora, M., Bogner, J., Sellaro, M., Wong, S.Y., Kostelac, C., Grayum, M.H., Keating, R.C., Ruckert, G., Naylor, M.F. and Hay, A., CATE Araceae, 17 Dec 2011.
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0