1. Family: Arecaceae Bercht. & J.Presl
    1. Borassus L.

      1. This genus is accepted, and its native range is Tropical & S. Africa, Madagascar, Tropical & Subtropical Asia.

    [FTEA]

    Palmae, John Dransfield. Flora of Tropical East Africa. 1994

    Habit
    Solitary, robust to massive, pleonanthic dioecious tree palms; stems sometimes ven-tricose, unbranched or branching due to injury
    Leaves
    Leaves massive palmate or costapal-mate, often long persisting but finally falling to leave a clean trunk; leaf-sheath short, not clearly distinct from the petiole, splitting longitudinally to produce a central triangular cleft; petiole stout, usually armed with irregularly curved and erose teeth along the margins, terminating in a conspicious adaxial hastula and a much smaller abaxial hastula; lamina divided into numerous induplicate usually bifid segments
    Inflorescences
    Inflorescences axillary, interfoliar, ♂ markedly differing from the ♀ Male inflorescence with an elongate peduncle bearing a prophyll and several bracts; partial inflorescences few-numerous, each borne in the axil of a rachis-bract, the branch-axis adnate to the main axis for some distance above the insertion; branch axis with a basal bare portion terminating in (1–)3 or more rachillae; rachillae massive, cylindrical, bearing connate imbricate bracts, also partly adnate to the axis to form pits, each enclosing a cincinnus of flowers and closed by the free tip of the bract; cincinus bearing 3 or more flowers Female inflorescence simple or with 1–2 branches, clothed in large imbricate and connate bracts
    Flowers
    Male flowers emerging one by one from the pits; sepals 3, connate into a shallowly or deeply lobed tube; corolla stalk-like at the base, lobes 3, imbricate; stamens 6, with subulate filaments and erect anthers; pistillode minute Female flowers massive, solitary, borne in the axils of these bracts, each subtended by 2 bracteoles; sepals 3, imbricate; petals 3, similar to the sepals; staminodes 6, forming a ring with minute anther rudiments; ovary globose, 3-locular, each locule with a single orthotropous ovule; stigmas 3, very short; septal nectaries conspicuous
    Male
    Male flowers emerging one by one from the pits; sepals 3, connate into a shallowly or deeply lobed tube; corolla stalk-like at the base, lobes 3, imbricate; stamens 6, with subulate filaments and erect anthers; pistillode minute Male inflorescence with an elongate peduncle bearing a prophyll and several bracts; partial inflorescences few-numerous, each borne in the axil of a rachis-bract, the branch-axis adnate to the main axis for some distance above the insertion; branch axis with a basal bare portion terminating in (1–)3 or more rachillae; rachillae massive, cylindrical, bearing connate imbricate bracts, also partly adnate to the axis to form pits, each enclosing a cincinnus of flowers and closed by the free tip of the bract; cincinus bearing 3 or more flowers
    Female
    Female flowers massive, solitary, borne in the axils of these bracts, each subtended by 2 bracteoles; sepals 3, imbricate; petals 3, similar to the sepals; staminodes 6, forming a ring with minute anther rudiments; ovary globose, 3-locular, each locule with a single orthotropous ovule; stigmas 3, very short; septal nectaries conspicuous Female inflorescence simple or with 1–2 branches, clothed in large imbricate and connate bracts
    Fruits
    Fruit massive, 1–3-seeded, borne within the persistent perianth-segments; epicarp usually smooth or cracked vertically; mesocarp fibrous and pulpy
    Seeds
    Germination remote tubular; eophyll simple. Seeds each enclosed in a separate endocarp; endosperm homogeneous with a central hollow; embryo apical
    [PW]
    Morphology
    Leaf (Tomlinson 1961), root (Seubert 1997).
    Distribution
    Six species have been recognised. They occur in Africa, Madagascar, north-eastern Arabia, through India and Southeast Asia to New Guinea and Australia. Borassus is one of the most widespread palm genera.
    Vernacular
    Toddy or wine palm, lontar, palmyra, or siwalan (Borassus flabellifer).
    Biology
    Borassus flabellifer can occur in some mountain districts of India at elevations of 500–800 m, and is also found on banks of rivers. It is most abundant, however, on low sandy plains near sea level where exposed to sun and winds. In Africa, B. aethiopum occurs in open secondary forest and savannah.
    Diagnostic
    Large dioecious tree fan palms of Africa, Madagascar, the Indian Subcontinent and Southeast Asia, and the drier parts of Malesia; distinctive in the leaves with spiny petiole margins, the spines often very irregularly shaped, and large fruit with the endocarp usually lacking internal flanges that penetrate the homogeneous endosperm.
    General Description
    Tall, robust, solitary, armed, pleonanthic, dioecious, tree palms. Stem massive, covered in a lattice of leaf bases abscising cleanly in older specimens, then rough, ringed with wide leaf scars. Leaves induplicate, strongly costapalmate; sheath open early in development, later with a wide triangular cleft at the base of the petiole; petiole deeply channelled adaxially, rounded abaxially, surfaces smooth to minutely rough, margins of sheath and petiole armed with coarse irregular teeth; adaxial hastula conspicuous, triangular or scalloped, abaxial hastula a low ridge (?always); blade suborbicular to flabellate, divided along adaxial folds to ca. 1/2 its length into regular, stiff single-fold segments, these shortly bifid, interfold filaments present or absent, surfaces smooth, ramenta or tomentum along abaxial costa and ridges of folds, midribs prominent abaxially, transverse veinlets conspicuous, short, numerous. Inflorescences interfoliar, shorter than the leaves, the staminate and pistillate dissimilar. Staminate inflorescence branched to 2 orders; peduncle very short; prophyll 2-keeled, with long tubular base, limb short, pointed, variously split apically; (?)peduncular bracts lacking; rachis also short, rachis bracts similar to the prophyll; first-order branches long, flattened, each bearing a prophyll and branched digitately into several (1–3) rachillae; rachillae large, catkin-like, elongate, bearing spirally arranged, imbricate bracts, connate laterally and distally to form large pits, each containing a reflexed cincinnus of ca. 30 staminate flowers, exserted singly in succession from the pit mouth. Staminate flowers each subtended by a long membranous bracteole; sepals 3, asymmetrical, connate only basally or to 2/3 their length, distinct lobes keeled, elongate, membranous, stiff; corolla with a long stalk-like base and 3 short, rounded lobes, ridged adaxially; stamens 6, filaments short, triangular, anthers medifixed, elongate, latrorse; pistillode small, conical. Pollen ellipsoidal, bi-symmetric; aperture a distal sulcus; ectexine tectate, reticulate or finely perforate-rugulate, rarely foveolate-reticulate, with psilate supratectal gemmae, aperture margin similar but often without supratectal gemmae; infratectum columellate; longest axis 42–85 µm [2/6]. Pistillate inflorescence unbranched or with a single first-order branch; peduncle short; prophyll tubular, pointed, 2-keeled, split ventrally about 1/2 its length; peduncular bracts few (2 or more), if present as long as or longer than the peduncle; rachilla massive, bearing large cupular bracts, the first few empty, the subsequent each subtending a single pistillate flower, several empty bracts above the flowers. Pistillate flowers large, each bearing 2 lateral cup-like, rounded, leathery, bracteoles; sepals 3 distinct, imbricate, thick, rounded; petals 3, similar to sepals; staminodes triangular, connate basally in a low cupule, sterile anthers present or not; gynoecium rounded, tricarpellate, with a central, basal septal nectary, stylar region hemispherical, stigma a low knob, carpels each with a basal, orthotropous ovule, and 2 lateral bodies, perhaps vestigial ovules. Fruit large, rounded, sometimes wider than long, bearing 1–3 seeds, stigmatic remains apical, perianth enlarged, persistent; epicarp smooth, mesocarp thick, fibrous, often fragrant, endocarp comprising 3 hard bony pyrenes. Seed shallowly to deeply bilobed, pointed, basally attached, endosperm homogeneous with a central hollow; embryo apical. Germination remote-tubular; eophyll undivided, elliptical. Cytology: 2n = 36.
    [PW]
    Use
    Borassus flabellifer is one of the most intensively used palms. Leaves have been used for writing; wood is valuable for building; inflorescences are tapped and the syrup, sugar, or alcohol may be a staple (Fox 1977).

    Images

    Distribution

    Native to:

    Bangladesh, Benin, Burkina, Cambodia, Cameroon, Central African Repu, Chad, Comoros, Congo, Ethiopia, Gambia, Ghana, Guinea, Guinea-Bissau, Gulf of Guinea Is., India, Ivory Coast, Jawa, Kenya, Laos, Lesser Sunda Is., Madagascar, Malawi, Mali, Mozambique, Myanmar, New Guinea, Niger, Nigeria, Northern Provinces, Senegal, Sri Lanka, Sudan, Tanzania, Togo, Uganda, Vietnam, Zambia, Zaïre, Zimbabwe

    Introduced into:

    China South-Central, Malaya, Mauritania, Socotra, Sulawesi, Thailand, Trinidad-Tobago

    Borassus L. appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    s.coll. [Cat. no. s.n.] K001132682
    s.coll. [Cat. no. s.n.] K001132684

    First published in Sp. Pl.: 1187 (1753)

    Accepted by

    • Bayton, R.P. (2007). A revision of Borassus L. (Arecaceae) Kew Bulletin 62: 561-586.
    • Govaerts, R. & Dransfield, J. (2005). World Checklist of Palms: 1-223. The Board of Trustees of the Royal Botanic Gardens, Kew.
    • Govaerts, R. (1996). World Checklist of Seed Plants 2(1, 2): 1-492. MIM, Deurne.

    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
    Flora of West Tropical Africa
    • F.T.A. 8: 117.
    • Sp. Pl. 1187 (1753)
    Flora of Tropical East Africa
    • Becc. in Palme Borass.: 2 (1924)
    • L., Gen. Pl., ed. 5: 494 (1754)
    • Sp. Pl.: 1187 (1753)

    Sources

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    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.
    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