Borassus flabellifer L., Sp. Pl. : 1187 (1753)

Primary tabs

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Bangladeshpresent (World Checklist of Arecaceae)B
Cambodiapresent (World Checklist of Arecaceae)B
China South-Centralpresent (World Checklist of Arecaceae)B
Indiapresent (World Checklist of Arecaceae)B
Jawapresent (World Checklist of Arecaceae)B
Laospresent (World Checklist of Arecaceae)B
Lesser Sunda Is.present (World Checklist of Arecaceae)B
Malayapresent (World Checklist of Arecaceae)B
Myanmarpresent (World Checklist of Arecaceae)B
Socotrapresent (World Checklist of Arecaceae)B
Sri Lankapresent (World Checklist of Arecaceae)B
Sulawesipresent (World Checklist of Arecaceae)B
Thailandpresent (World Checklist of Arecaceae)B
Vietnampresent (World Checklist of Arecaceae)B
South and Southeast Asia. Determining the ‘natural’ distribution of Borassus flabellifer is essentially impossible as it is a widely planted crop plant. It is largely restricted to areas with seasonal rainfall and ranges from western India through Indochina to the Lesser Sunda Islands of Indonesia. Populations in China, Malaysia and Pakistan may be introduced (Whitmore 1973; Malik 1984; Pei 1991). Borassus flabellifer was noted to occur in Queensland, Australia by Bailey (1902). A seedling was collected from a small population of mature palms and cultivated in the garden of Frank L. Jardine in Somerset on the Cape York Peninsula of northern Queensland. Jones (1984) noted that the palm was still present in the garden of Jardine’s abandoned house, but the original population was never located and the natural occurrence of Borassus in Australia is doubtful. The Borassus palms on the island of Soqotra have tentatively been assigned to B. flabellifer. Soqotra is geographically closer to Africa and the palms were identified as the African B. aethiopum by Miller & Morris (2004). The available herbarium material does not allow for a conclusive identification (the diagnostic fruits and petiole spines are missing), but a photograph presented by Miller & Morris (2004) shows a mature plant without a ventricose stem. This suggests that the palms, which were introduced to the island, are B. flabellifer. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Discussion

  • A number of nomenclatural problems were uncovered while investigating the synonymy of B. flabellifer. The account of Borassus flabelliformis L. in Systema Vegetabilium (Linnaeus 1774) matches exactly that of B. flabellifer in Species Plantarum (Linnaeus 1753), and the epithets are similar, suggesting that the former is an orthographic variant of the latter. It could be argued that the change in epithet was intentional, but this would render B. flabelliformis illegitimate, as both names are based on the same type material (Challis, pers. comm.). When describing Lontarus domestica, Gaertner (1788) cited the same material as Linnaeus (1753) plus an un-named Banks specimen, which could not be located after a thorough search of the Banks collection at BM (Vickery pers. comm.). Pholidocarpus tunicatus is attributed to Wendland (1878: 235) in a number of publications including Govaerts and Dransfield (2005). However, Wendland did not make the combination, but rather, states under Borassus tunicata Lour., “vide Pholidocarpus” (Merrill 1935: 92). The name does not appear in the account of Pholidocarpus, nor in the index; the combination is therefore attributed to Jackson in Index Kewensis (1894: 502). No original material could be found in the Loureiro collection at BM to typify Borassus tunicata (Vickery pers. comm.). Borassus sundaicus was placed in synonymy with B. flabellifer by Govaerts and Dransfield (2005), though not noted as a new synonym. The diagnostic characters cited by Beccari (shape of perianth segments, endocarp crest size, seed shape) are largely continuous when examined across the Asian material. The only qualitative characters cited are leaf scales (present in B. flabellifer and absent from B. sundaicus), and the arrangement of perianth segments in the fruit (imbricate in B. sundaicus, but not in B. flabellifer). In most Borassus species, leaf scales and indumentum are present on immature leaves, but they erode as the leaves mature. In addition, a degree of overlap can be observed in the perianth segments of most Borassus species. Therefore these characters are not taxonomically informative. Pollen from an Indonesian specimen of B. flabellifer (Fox s.n.) was significantly larger than that from either the Thai or Sri Lankan specimens. A sample of ten pollen grains was measured from each specimen; the Indonesian pollen was 70 – 95 μm long (mean 84.8 μm) while pollen from Sri Lanka was 45 – 65 μm long (mean 53.6 μm) and pollen from Thailand was 51 – 72 μm long (mean 60 μm). There were no noticeable structural differences between the pollen samples. Given the rather limited sampling of Indonesian Borassus, it is difficult to determine whether this aberration is distinctive or whether it fits within the range of variation exhibited by B. flabellifer across Asia. However, after examination of images of the type specimen of B. sundaicus, I can find no additional morphological characters to distinguish this taxon from B. flabellifer. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Biology And Ecology

  • It is difficult to determine the original habitat of B. flabellifer as its distribution is so heavily influenced by man. It occurs between sea level and 800 metres, though is more abundant at low altitude and is particularly common in coastal areas with sandy or alluvial soils and in areas with permanent soil moisture such as flood plains and river valleys. It is commonly grown along the margins of rice paddies forming one of the most distinctive landscapes of Southeast Asia. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Conservation

  • Least concern. Borassus flabellifer is widely distributed and is common in cultivation. The abundance of products extracted from it will effectively ensure its continued survival. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Common Name

  • Kerigi (Soqotra), Mak tan kok (Lao), Panna-maram (Tamil, Sri Lanka), Taan, Than or T¯an (Thai). There are many other names applied to this widespread species (see Kovoor 1983), but the name palmyrah (or palmyra), derived from the Portuguese palmeira, has become the internationally familiar vernacular name. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Etymology

  • The epithet ‘flabellifer’ translates as ‘producing fans’ and refers to the palmate leaves. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Uses

  • Almost every part of the palmyrah palm can be used. The wood is thought to be termite resistant and is used for construction (houses, canoes, fence posts etc.). The leaves are used for thatch, weaving and for making containers for some foodstuffs. The leaflets of B. flabellifer (together with those of Corypha umbraculifera L.) are traditionally used as a writing surface. They are marked using a hot metal stylus with the parallel veins providing a convenient line upon which to write (Sankaralingham & Hameed Khan 2001). Palmyrah provides a variety of foods; the fruits, undeveloped endosperm and apical bud (palm cabbage) are consumed and the inflorescences are tapped for the sweet sap. This can be fermented into palm wine or the sugar can be crystallised. On some Indonesian islands, this sugar is the primary source of carbohydrates (Fox 1977). For a review of the uses of B. flabellifer, see Kovoor (1983) and Morton (1988). (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Description

  • Stem to 20 m tall, grey with well-defined leaf scars, not ventricose, but often enlarged at the base, branching occasionally when damaged. Leaves petiole and sheath 150 – 180 cm long; petiole 4 – 6(– 7) cm wide at midpoint, robust, bright yellow, margins black with short (0.3 – 1.3 cm) black erose teeth; costa 60 – 110 cm long; adaxial hastula conspicuous, abaxial hastula rudimentary; lamina radius to 150 cm maximum, dense adaxial and abaxial indumentum on the ribs of some juvenile leaves, leaflets ~62, 4.2 – 9.5 cm wide, apices acute and entire or splitting longitudinally with age, shortest leaflet 13 – 39 cm long, leaf divided to 30 – 100 cm; commissural veins 11 – 18 per cm, leaf anatomy isolateral. Staminate inflorescences branched to two orders, upper subtending branches terminating in 1 – 3(– 4) rachillae; rachillae green to brown and catkin-like, 23 – 50 cm long and 1.8 – 2.5 cm diameter, sometimes with a mamilliform apex, rachilla bracts forming pits containing a cincinnus of 4 – 7 flowers. Pistillate inflorescences usually spicate (branched inflorescence pictured in the lectotype), flower-bearing portion 12 – 85 cm long with 5 – 20 flowers arranged spirally. Staminate flowers exserted from pits individually, 0.24 – 0.6 cm long, bracteoles 0.4 – 0.7 × 0.1 – 0.3 cm, calyx 0.3 × 0.15 cm and shallowly divided into three sepals, petal lobes 0.1 × 0.1 cm; stamens 6 with very short filaments, 0.2 × 0.03 cm, anthers, 0.05 × 0.03 cm; pistillode minute. Pollen monosulcate, elliptical, 48 – 95 μm long, aperture 40 – 95 μm long, polar axis 30 – 89 μm long; tectum perforate, sparsely covered with supratectal gemmae. Pistillate flowers 3 × 3 cm; bracteoles large, 2 cm diam., sepals 1.5 × 2 cm, petals 1 × 1.5 cm. Fruits massive, 8.5 – 13 × 7.5 – 16.5 cm, yellowish black, ovoid and rounded or flattened at the apex; produced inside persistent perianth segments; epicarp coriaceous, mesocarp pulp yellow, pyrenes 1 – 3, 6.1 – 10.8 cm × 4.4 – 8.5 cm × 3.1 – 4.6 cm, somewhat bilobed; most pyrenes with one or two external, longitudinal furrows; internal flanges absent. (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Materials Examined

  • BANGLADESH. Chittagong, 1867 (♂), JSHVJJ s.n. (K!); Chittagong Hill Tracts, March 1880, Gamble 7781 (K!); Dhaka, 25 March 1868, Clarke 6673 (FI!). INDIA. Orissa State: Anugul, 19 March 1903 (♂), Haines 4034 (K!); Tamil Nadu State: Tiruchchirappalli, 4 April 1974 (♀), Mathew 7145 (K!); Madras [Chennai], Kristna Distr., 1 Jan. 1883 (♂), Gamble 18581 (K!); Uttar Pradesh State: Banda, 9 May 1901 (♂), Bell 320 (K!); West Bengal State: cultivated, Calcutta [Kolkata] Botanic Gardens, 1869 (♀ & ♂), Wallich 8622 (K!, K-W!); same locality, 1906 (♀ & ♂), Gage s.n. (FI!); Calcutta [Kolkata], 1881 (♀), King 69 (K!). INDONESIA. East Nusa Tenggara Prov.: West Timor, Kupang, 1973 (♀ & ♂), Fox s.n. (BH!); South East Sulawesi Prov.: Pulau Buton, 2004 (♀), Rustiami 222 (BO, K!). MALAYSIA. Kelantan State: Tumpat, 5 May 1937 (♀), Corner 32784 (BH!, K!). SINGAPORE. Cultivated, Singapore Botanic Garden (♀), Furtado s.n. (BH!); same locality (♂), Furtado 32447 (BH!, K!). SRI LANKA. Central Prov.: cultivated, Royal Botanic Gardens, Peradeniya, 22 July 1986 (♀ & ♂), Rutherford 115 (K!); North Central Prov.: 5 km from Anuradhapura, 19 Sept. 1989 (♀ & ♂), Zoysa 49 (K!). THAILAND. Unknown locality, 1859 (♂), Schomburgk s.n. (BH!, K!); Bangkok Prov.: Bangkok, 30 May 1906 (♂), Kerr 10708 (AAU!, BM!, K!); Bangkok, 20 May 1926 (♂), Marcan 2097, 2098 (BM!); 39 km S of Bangkok, 31 July 1963 (♀ & ♂), King 5565 (BH!); Nonthaburi Prov.: no locality, 24 May 1997 (♂), Niyomdham 5038 (AAU!, K!); Phichit Prov.: 81.5 km from Nakhon Sawan on Route 117, 26 April 2002 (♂), Wilkin et al. 1160 (K!); Rayong Prov.: Salut, Klaeng, 14 March 1928 (♀), Kerr 14581 (BM!); Songkhla Prov.: Road from Songkhla – Sathing Phra, 11 Nov. 1990 (♀ & ♂), Barfod 41256 (AAU!); Ban si Chai Noi, 7 March 1994 (♀ & ♂), Barfod 45286, 45287 (AAU!). YEMEN. Soqotra, unknown locality, 1880 (♂), Balfour s.n. (K!); Hadiboh Plains, 1967 (♀), Smith s.n. (K!). (R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007)A

Bibliography

A. R.P. Bayton, A revision of Borassus L. (Arecaceae). 2007
B. World Checklist of Arecaceae