Elaeis Jacq.
  • Select. Stirp. Amer. Hist.: 280 (1763) 


Notes: Distribution: Trop. Africa, C. & S. Trop. America

General Description

Moderate to robust, solitary, short to tall, armed, pleonanthic, monoecious palms. Stem procumbent or erect, bearing persistent leaf bases, eventually becoming bare, the internodes short, leaf scars wide, oblique. Leaves many in the crown, pinnate, withering and not abscising neatly except in tall-trunked individuals; sheath tubular at first, later disintegrating into an interwoven mass of fibres, those fibres attached to the base of the petiole remaining as regularly spaced, broad, flattened spines; petiole conspicuous, adaxially channelled, abaxially angled, bearing caducous tomentum, the margins armed with regularly spaced fibre spines, distally (strictly speaking the proximal part of the rachis) with margins armed with short, triangular, bulbous-based spines representing the pulvini and midribs of the proximal few vestigial leaflets, the blades of which soon disintegrate on leaf expansion; rachis curving or straight, adaxially angled, abaxially curved or flattened; leaflets numerous, single-fold, regularly arranged or slightly grouped and held in different planes, giving the whole leaf a plumose appearance, linear, gradually tapering to acute tips, sometimes with bands of caducous scales, midribs prominent, transverse veinlets very short, inconspicuous. Inflorescences interfoliar, solitary, short and condensed, unisexual (except as monstrosities), usually several adjacent axils producing inflorescences of one sex followed by several producing the other sex, branching to 1 order; peduncle short, ± elliptic in cross-section; prophyll short, tubular and flattened, 2-keeled, tomentose, included within the subtending leaf sheath, thick, traversed by numerous, thick, longitudinal fibres, disintegrating distally into a mass of fibres, the larger fibres spine-like; first peduncular bract inserted some distance from the prophyll, tubular, fibrous, thinner than the prophyll, distally disintegrating into a fibrous mass, and splitting longitudinally, subsequent peduncular bracts small, not sheathing, narrow triangular, with sharp tips, striate; rachis shorter than, ± equalling, or slightly longer than the peduncle, tomentose, bearing numerous, spirally arranged, narrow triangular, membranous to coriaceous, acute bracts, each subtending a rachilla; staminate rachillae ± cylindrical, catkin-like, often somewhat angled due to close packing, tomentose, densely floriferous except at the ± spine-like tip where bare of flowers and bracts, the flowers solitary, borne in deep, spirally arranged pits, pistillate rachillae more massive than the staminate, bearing fewer flowers, the tips prolonged into a woody spine, each rachilla proximally bearing lax, ± superficial or only partially sunken, spirally arranged membranous rachilla bracts; bracts short, acute, or prolonged into a straight or flexuous spine-like tip, each subtending a solitary flower. Staminate flowers small, only slightly protruding from the pits at anthesis; sepals 3, distinct, unequal, ± rectangular, membranous, the edges not meeting in bud, abaxially keeled; petals 3, distinct, ± ovate, ± equalling the sepals, valvate, very thin; stamens 6, exserted at anthesis, filaments broad, fleshy, united laterally to form a tube, with 6 short, distinct, reflexed, abruptly narrowed tips, anthers ± rectangular, ± versatile, introrse; pistillode columnar, trifid, slightly shorter than the staminal tube. Pollen either ellipsoidal, slight to obvious asymmetry (Elaeis oleifera), or oblate triangular (E. guineensis); aperture a distal sulcus or trichotomosulcus; ectexine perforate scabrate or perforate rugulate, aperture margin (ellipsoid pollen) similar, aperture margin (trichotomosulcate pollen) broad and psilate or psilate-perforate; infratectum columellate; longest axis ranges from 31–39 µm [2/2]. Pistillate flowers much larger than the staminate, borne with 2 acute or spine-tipped bracteoles; sepals 3, distinct, imbricate, rather thin; petals 3, distinct, imbricate, rather thin; staminodal ring low, 6-pointed, tanniniferous; gynoecium columnar to ovoid, trilocular, triovulate, stigmas 3, fleshy, reflexed, ± 3-angled, ovules orthotropous, attached centrally. Fruit 1–(rarely more)-seeded, ± ovoid but basally angled by close packing, variously orange or yellow, overlain with deep violet or black in exposed parts, apically beaked, stigmatic remains apical; epicarp smooth, mesocarp thick, fleshy, oily, fibrous, endocarp black, woody and very hard, variously ovoid, flattened or angled, with 3 apical pores. Seed basally attached with coarse, reticulate raphe branches, endosperm homogeneous, with or without a central cavity; embryo ± apical, opposite a pore. Germination adjacent-ligular; eophyll entire, lanceolate. Cytology: 2n = 32.

Diagnostic Description

Solitary pinnate-leaved palms from South and Central America and humid Tropical Africa, including the African oil palm of commerce, distinctive in fibre spines and spines formed from leaflet midribs at the base of the leaf, and highly condensed unisexual inflorescences borne among the leaf bases, both male and female borne on the same tree.

Morphology

Leaf (Tomlinson 1961), phloem (Parthasarathy 1980), root (Seubert 1998a, 1998b), stegmata (Killmann and Hong 1989) and gynoecium (Uhl and Moore 1971).

Biology

In the wild, it occurs on the margins of humid forest and along watercourses in drier areas. Elaeis oleifera is native to central and northern South America, and is frequent on poorly drained, sandy soils and in savannas. In Costa Rica, it is found in palm swamp and some mangrove communities (Allen 1956).

Distribution

Two species. Elaeis guineensis is native to the more humid areas of tropical Africa, possibly introduced in Madagascar, now widely cultivated throughout the humid tropics as the most productive perennial oil crop, and frequently naturalised.

Uses

Elaeis guineensis is the most important commercial oil-producing plant in the tropics, and is used locally as a source of wine, thatch and building materials. Even waste endocarp has been used as road metalling. For further details, see Hartley (1988), and for references, Johnson (1983b).

Common Names

African oil palm (Elaeis guineensis), American oil palm (E. oleifera).

Distribution Map

 
  • Native distribution
  • Introduced distribution
Found in
  • Africa East Tropical Africa Kenya
  • Tanzania
  • Uganda
  • Northeast Tropical Africa Chad
  • South Tropical Africa Angola
  • Malawi
  • Mozambique
  • West Tropical Africa Benin
  • Gambia, The
  • Ghana
  • Guinea
  • Guinea-Bissau
  • Ivory Coast
  • Liberia
  • Nigeria
  • Senegal
  • Sierra Leone
  • Togo
  • West-Central Tropical Africa Burundi
  • Cameroon
  • Central African Republic
  • Congo
  • Gabon
  • Gulf of Guinea Is.
  • Rwanda
  • Zaire
  • Southern America Brazil Brazil North
  • Central America Costa Rica
  • Honduras
  • Nicaragua
  • Panamá
  • Northern South America French Guiana
  • Suriname
  • Western South America Colombia
  • Ecuador
  • Peru
Introduced into
  • Africa West Tropical Africa Burkina
  • Western Indian Ocean Comoros
  • Madagascar
  • Asia-Tropical Indian Subcontinent Sri Lanka
  • Indo-China Andaman Is.
  • Nicobar Is.
  • Malesia Malaya
  • Sumatera
  • Papuasia Bismarck Archipelago
  • Pacific Northwestern Pacific Caroline Is.
  • South-Central Pacific Society Is.
  • Southwestern Pacific Fiji
  • Southern America Caribbean Dominican Republic
  • Haiti
  • Puerto Rico
  • Central America El Salvador

  Bibliography

  • 1 J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008
  • 2 Govaerts, R. & Dransfield, J. (2005). World Checklist of Palms: 1-223. The Board of Trustees of the Royal Botanic Gardens, Kew.

 Information From

Palmweb - Palms of the World Online
http://www.palmweb.org
Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet http://www.palmweb.org. Accessed on 21/04/2013
  • A Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
  • B http://creativecommons.org/publicdomain/zero/1.0
eMonocot
http://e-monocot.org
eMonocot. (2010, 1st November). Retrieved Wednesday, 8th February, 2012, from http://e-monocot.org.
  • C Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
World Checklist of Selected Plant Families
http://apps.kew.org/wcsp/
WCSP 2014. 'World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://apps.kew.org/wcsp/ Retrieved 2011 onwards
  • D See http://kew.org/about-kew/website-information/legal-notices/index.htm You may use data on these Terms and Conditions and on further condition that: The data is not used for commercial purposes; You may copy and retain data solely for scholarly, educational or research purposes; You may not publish our data, except for small extracts provided for illustrative purposes and duly acknowledged; You acknowledge the source of the data by the words "With the permission of the Trustees of the Royal Botanic Gardens, Kew" in a position which is reasonably prominent in view of your use of the data; Any other use of data or any other content from this website may only be made with our prior written agreement.