1. Family: Arecaceae Bercht. & J.Presl
    1. Roystonea O.F.Cook

      1. This genus is accepted, and its native range is S. Florida, Caribbean, Mexico to Venezuela.

    [PW]
    Biology
    Primarily palms of the lowlands. Some species are thought to be indicators of good soil conditions. Most of their original habitats are now cleared for agriculture.
    Vernacular
    Royal palms, mountain cabbage palm (Roystonea altissima).
    Morphology
    Leaf (Tomlinson 1961), root (Seubert 1998a, 1998b).
    General Description
    Tall, stout, solitary, unarmed, pleonanthic, monoecious palms. Stem columnar, variously tapered or swollen, tan, grey, or white, ringed by prominent or obscure leaf scars. Leaves pinnate; sheath tubular, large, forming a prominent crownshaft; petiole relatively short, channelled adaxially, rounded abaxially; leaflets narrow, elongate, tapering to a point, single-fold, held in one plane or variously inserted, crowded or in groups, rather thin, midrib only or midrib and other longitudinal veins raised abaxially, hairs frequent and scales prominent along the midrib, transverse veinlets evident abaxially. Inflorescences infrafoliar, massive, branched to 3(–4) orders; peduncle very short, stout; prophyll tubular, elongate, strongly 2-keeled laterally, truncate, leathery, green, splitting apically; peduncular bract 2 to 3 times as long as the prophyll, terete, pointed, glabrous, leathery, green, splitting longitudinally; rachis much longer than the peduncle, bearing small, pointed, spirally inserted bracts; rachillae very long, slender and pendulous or short, stout and variously divaricate, straight or undulate, white when first exposed due to copious free scales; rachilla bracts spirally arranged, small, membranous, tapered, subtending widely spaced triads of flowers proximally and paired or solitary staminate flowers distally; floral bracteoles small, thin, membranous. Staminate flowers nearly symmetrical, larger than the pistillate buds at anthesis; sepals 3, distinct, triangular, imbricate, very short; petals 3, distinct, ovate, valvate, about 10 times the length of the sepals, tips thickened; stamens 6–12, filaments awl-shaped, erect in bud; anthers elongate, versatile, sagittate basally, dorsifixed near the middle, latrorse, connective tanniniferous; pistillode subglobose or trifid. Pollen grains ellipsoidal, occasionally oblate triangular, with slight or obvious asymmetry; aperture a distal sulcus, occasionally a trichotomosulcus; ectexine tectate, finely or coarsely perforate or perforate-rugulate, aperture margin slightly finer than main tectum; infratectum columellate; longest axis 61–66 µm [4/10]. Pistillate flowers nearly conical to shortly ovoid; sepals 3, distinct, very short, broadly imbricate, rounded; petals 3, ovate, connate about 1/2 their length, valvate distally, more than twice as long as the sepals; staminodes 6, connate in a 6-lobed cupule adnate to the corolla basally; gynoecium subglobose, unilocular, uniovulate, style not distinct, stigmas 3, recurved, ovule laterally attached, form unknown. Fruit obovoid to oblong-ellipsoidal or subglobose, stigmatic remains nearly basal, perianth persistent; epicarp smooth, thin, mesocarp of pale parenchyma over a layer of thin, flat, anastomosing fibres next to the endocarp, endocarp thin, horny, fragile, somewhat operculate at the base, roughened and often ± adherent to the seed adaxially. Seed ellipsoidal, brown, hilum large, circular, lateral, raphe branches fine, radiating from the hilum, endosperm homogeneous; embryo nearly basal. Germination adjacent-ligular; eophyll entire. Cytology: 2n = 36, 38.
    Distribution
    Ten species found throughout the islands of the Caribbean and bordering continental areas such as Florida, Mexico, eastern Central America, and northern South America.
    Diagnostic
    The Royal Palms — spectacular majestic solitary pinnate-leaved palms from the Craibbean islands and neighbouring parts of North, Central and South America; crownshaft is very conspicuous and the inflorescence branched to at least 4 orders with rather stiff spreading rachillae.
    [PW]
    Use
    Roystonea species are among the most elegant of the large palms and are widely cultivated in both hemispheres. Fruits are high in oil content and are used as pig food. The ‘cabbage’ of R. oleracea is edible.

    Images

    Distribution

    Native to:

    Bahamas, Belize, Cayman Is., Colombia, Cuba, Dominican Republic, Florida, Haiti, Honduras, Jamaica, Leeward Is., Mexico Gulf, Mexico Southeast, Nicaragua, Puerto Rico, Trinidad-Tobago, Venezuela, Venezuelan Antilles, Windward Is.

    Introduced into:

    El Salvador, Guyana, Mauritius, New Caledonia, Panamá, Réunion

    Roystonea O.F.Cook appears in other Kew resources:

    First published in Science, ser. 2, 12: 479 (1900)

    Accepted by

    • Govaerts, R. & Dransfield, J. (2005). World Checklist of Palms: 1-223. The Board of Trustees of the Royal Botanic Gardens, Kew.

    Literature

    Palmweb - Palms of the World Online
    • J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008

    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. 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 2018. 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

    Palmweb - Palms of the World Online
    Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet http://www.palmweb.org. Accessed on 21/04/2013
    Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License http://creativecommons.org/licenses/by-nc-sa/3.0