1. Family: Arecaceae Bercht. & J.Presl
    1. Genus: Arenga Labill. ex DC.
      1. Arenga retroflorescens H.E.Moore & Meijer

        This species is accepted, and its native range is Borneo (Sabah).

    [PW]
    General Description
    Caespitose and colonial with rhizomes ca. 2 cm. in diam. and stems, when developed, prominently ridged at the nodes, to 8 dm. high, 3.8 cm. in diam., internodes to ca. 5 cm. long. Leaves several in a tuft from the ground in young plants or apical on older stems; sheaths fibrous, blackish, densely brown-tomentose at least basally, split nearly to the base opposite the petiole and fibrous-margined, produced apically in a fibrous ligule to ca. 25 cm. long between the petiole and the stem; petiole to 1.8 m. long, buff- or brown-tomentose at the base next to the sheath when young and there becoming densely darkbrown puncticulate in age, elsewhere rounded below, channelled above and covered for most of its length when young with brown membranous appressed medifixed narrow scales but at length becoming merely puncticulate; rachis 1.15-1.3 m. long, rounded below and when young densely covered with scales hke those of the petiole, flattened with a central ridge and less scaly above; pinnae 22-23 on each side, the Iower 3-5 on each side separated from the remainder by ca. 13 cm. and forming a cluster, the remainder more or less evenly spaced at intervals of 5-8 cm., all green above, pale with a thin waxy brown-puncticulate coat and brownscaly midnerve below, exauriculate at the base, narrowly obcuneate with margins sharply toothed only near and at the irregularly truncate apex, the basal pinnae of a young leaf to 34 cm. long, 1.5-3 cm. wide, median pinnae to ca. 43 cm. long, 2.3 cm. wide, terminal pinna ca. 16 cm. long, 3 cm. wide, those from a mature leaf usually shorter and 1.9-2.5 cm. wide. Inflorescences developing in acropetal sequence, emerging from the leaf bases on young plants and penetrating the sheaths on older stems, spicate, erect, apparently unisexual; staminate inflorescence ca. 29 cm. long, enclosed by about 9 bracts, those at the base short, those above progressively longer and soon breaking into black fibers, the uppermost longer than the spike; peduncle 18 cm. long; spike 11 cm. long, 2 cm. in diam., very densely flowered; staminate flowers 9 mm. long, reddish in bud, subtended by prominent sepal-like bracteoles, sepals 3 mm. high, strongly, gibbous at the base, the margins rounded, more or less crenulate and minutely ciliate, petals acute but incurved in bud to form an obtuse and slightly depressed apex, 9 mm. long, 5 mm. wide, stamens ca. 36, the filaments very short, anthers linear, acute or even apiculate to emarginate at apex: pistillate spike shorter than the staminate but with bracts extended much beyond it, the whole inflorescence including bracts ca. 35 cm. long; peduncle ca. 9 cm. long; spike 10 cm. long, nearly or quite enclosed by the black bract fibers: pistillate flowers 10 mm. high, red-brown, subtended by a pair of marginally imbricate crenulate bracteoles 3 mm. high, sepals 5 mm. high, 8 mm. wide, corolla 10 mm. high, the tube only 2 mm. high, lobes 8 mm. long, staminodes absent (?), pistil strongly triquetrous, 8 mm. high at anthesis, trilocular, triovulate. Fruit (immature) strongly triquetrous, 1.7 cm. high, 2.2 cm. in diam., trilocular with 2 (-3?) seeds, these 9 mm. high when not fully developed but the locule 10 mm. high, endosperm homogeneous.

    Images

    Distribution

    Arenga retroflorescens H.E.Moore & Meijer appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Moore, H.E. Jr. [9162], Sabah K000207886 isotype
    Moore, H.E. Jr. [9162], Sabah K000207885 isotype
    Moore, H.E. Jr. [9162], Sabah K000207887 isotype
    Moore, H.E. Jr. [9162], Sabah K000207884 isotype

    First published in Principes 9: 100 (1965)

    Accepted by

    • Govaerts, R. & Dransfield, J. (2005). World Checklist of Palms: 1-223. The Board of Trustees of the Royal Botanic Gardens, Kew.
    • Govaerts, R. (1995). World Checklist of Seed Plants 1(1, 2): 1-483, 1-529. MIM, Deurne.

    Literature

    Palmweb - Palms of the World Online
    • H. E. Moore Jr. & W. Meijer, A new species of Arenga from Borneo in Principes 9. 1965

    Sources

    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.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. 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 2019. 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