Borassodendron Becc.
  • Webbia 4: 359 (1914) 


Notes: Distribution: Thailand to W. Malesia

General Description

Robust, solitary, unarmed, pleonanthic, dioecious, tree palms. Stem erect, ringed with close leaf scars. Leaves induplicate, very briefly costapalmate, marcescent in immature individuals, neatly abscising under their own weight in mature trunked individuals; sheath becoming fibrous marginally, narrow, glabrous but tomentose abaxially along the margins, with a conspicuous triangular cleft below the petiole; petiole robust, covered with caducous indumentum, adaxially deeply channelled, abaxially rounded, the margins smooth, very hard and very sharp; adaxial hastula well developed, abaxial hastula absent; blade divided nearly to the insertion into compound segments, these further divided rather irregularly to 1/4–2/3 the radius into single-fold segments, in turn shallowly divided along the abaxial folds, interfold filaments persisting, the segment surfaces similar in colour or with white indumentum beneath, blade with bands of brown caducous scales, longitudinal veins and transverse veinlets prominent. Inflorescences interfoliar, strongly dimorphic, ± pendulous. Staminate inflorescence branched to 2 orders, with a short to long peduncle; prophyll large, 2-keeled, tubular near the base, inflated distally, splitting along much of its length, densely covered in caducous indumentum, tending to disintegrate at the tip and margins into fibres; peduncular bracts 1–few, like the prophyll but with a single keel; rachis shorter or longer than the peduncle; rachis bracts like the peduncular; first-order branches distant or crowded, bare, semicircular in cross-section, with sharp edges, short or long, bearing 1–5 robust catkin-like rachillae crowded at the tip, each subtended by a small triangular bract; rachillae close or diverging, bearing a tight spiral of large scaly or hairy, imbricate bracts, connate to each other laterally and adnate to the axis to form pits, each pit containing a cincinnus of 2–6 flowers, floral bracteoles spathulate. Staminate flowers exserted one at a time from the pit; calyx membranous, tubular, tipped with 3 short triangular lobes, most of the calyx remaining included within the pit; corolla with a long stalk-like base carrying the rest of the flower out of the pit, petals 3, ±imbricate, elongate; stamens 6–15 with very short filaments and elongate latrorse anthers; pistillode minute or absent. Pollen brevi-ellipsoidal to oblate-spheroidal, bi-symmetric; aperture a distal brevi-sulcus or a single large pore; ectexine tectate, coarsely foveolate or reticulate, aperture margin psilate; infratectum columellate; longest axis 60–85 µm [2/2]. Pistillate inflorescence unbranched or with up to 4 branches; prophyll, peduncular bracts and rachis bracts as in the staminate inflorescence, inflorescence axis, where unbranched, terminating in a rachilla, where branched, having rachillae borne singly at the tip of bare, flattened first-order branches as in the staminate inflorescence; rachillae short to long, bearing a spiral of large hairy, frequently notched, scaly, imbricate bracts, connate to each other and adnate to the axis to form shallow pits (Borassodendron machadonis) or almost free but closely overlapping (B. borneense), each subtending a solitary pistillate flower (or abortive flower), the rachilla tip frequently bearing sterile bracts, sometimes with an apparently terminal flower, the bract margins frequently erose. Pistillate flowers sessile, ± superficial or partially sunken in pits, each surrounded by 2 large ovate, irregularly margined bracteoles; sepals 3, distinct, ovate, imbricate, the margins ± notched; petals 3, distinct, ovate, similar to the sepals; staminodal ring short, with 6–9 teeth bearing minute empty anthers; gynoecium globose, trilocular, triovulate, tipped with 3 fleshy approximate stigmas, ovule form unknown. Fruit large (1–2)–3-seeded, stigmatic remains apical; epicarp smooth, mesocarp fibrous, the interfibre parenchyma becoming sweet, fragrant, and fleshy at maturity, endocarp comprising 3 separate pyrenes with thick stony walls, walls with 8–12 shallow internal, longitudinal ridges penetrating the seed. Seed grooved longitudinally by the pyrene ridges, endosperm homogeneous, with a slight central hollow; embryo apical. Germination remote-tubular; eophyll palmate with ca. 5 segments. Cytology not studied.

Diagnostic Description

Large dioecious tree fan palms of tropical rain forest in South Thailand and Peninsular Malaysia and Borneo, distinctive in the leaves with razor-sharp petiole margins and large fruit with the endocarp with internal flanges that penetrate the homogeneous endosperm.

Morphology

Leaf (Tomlinson 1961), root (Seubert 1997).

Biology

Borassodendron machadonis is a rare palm, sometimes found in areas of deep soil on limestone hills, sometimes on ridges in hill Dipterocarp forest. In Borneo, B. borneense can be locally abundant on hills in the lowlands but is absent from wide areas of apparently suitable forest. The young leaves of B. borneense are eaten by orangutan, which can cause considerable damage; the same animals may be responsible for dispersal.

Distribution

Two species, Borassodendron machadonis in southern Thailand and northern Peninsular Malaysia, B. borneense in Borneo.

Uses

The ‘cabbage’ of Borassodendron borneense is edible and is sometimes sold in Bornean village markets.

Common Names

Bindang.

Distribution Map

 
  • Native distribution
Found in
  • Asia-Tropical Indo-China Myanmar
  • Thailand
  • Malesia Borneo
  • Malaya

  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.
  • 3 Govaerts, R. (1996). World Checklist of Seed Plants 2(1, 2): 1-492. Continental Publishing, Deurne.

 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.