Phoenix loureiroi Kunth, Enum. Pl. 3: 257 (1841)

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Distribution

Sub-Himalayan belt southwards through India, and eastwards through Indochina to southern China (including the islands of Hong Kong and Macao), Taiwan and to Batanes and Sabtang Islands of the Philippines. (Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae))A

Discussion

  • The group of Phoenix palms from Asia that have been variously known as P. humilis, P. hanceana and P. loureiri are referred to here as the 'R loureiri complex'. Confusion has surrounded the taxonomy of the complex, which has long been poorly understood. Two taxonomic approaches can be adopted. The complex can be treated as one polymorphic species, or an attempt can be made to recognise distinct taxa within the complex with formal taxonomic status conferred upon them. The former approach was adopted by Moore (1963a) who recognised the complex as one wide-ranging species, P. loureiri. The latter approach was taken by Beccari (1890) in his monograph of the genus. He treated the 'P. loureiri complex' as one species, P. humilis, comprising five closely-related varieties ranging from India to the Far East. Beccari (1890) acknowledged that varieties of P. humilis were not supported by stable taxonomic characters, and refers to them as 'regional forms'. Beccari (1890) thought P. humilis var. hanceana the most distinct variety, and later gave it species status as P. hanceana, itself comprising three varieties from southern China and Hong Kong, Taiwan and the Philippines (Beccari 1908). An attempt has been made here to find support for distinct taxa within the 'P. loureiri complex' using a combination of field, herbarium, anatomical and molecular data. Field data supports Beccari's (1890) observation that the 'R loureiri complex' is very adaptable and occurs in a wide variety of climates and habitats. It is this adaptability which may be the cause of polymorphism in the group. Molecular data group all members of the complex together and do not support any division of the complex into distinct taxa. Herbarium and anatomical studies have provided data which split the complex into two groups. Each group comprises a number of P. humilis varieties as defined by Beccari (1890, 1908). The taxa referred to by Beccari (1890) as P. humilis var. loureiri and var. hanceana of Indochina and the Far East respectively, have continuous strips of sclerotic, tannin-filled cells along the leaflet margins and discontinuous patches of such cells in the abaxial midrib region. In contrast, the Indian varieties of Beccari (1890), P. humilis var. typica, var. pedunculata and var. robusta, lack sclerotic, tannin-filled cells. Although the five P. humilis varieties (Beccari 1890) have been found to reflect certain geographical trends in morphological variation within the complex, I do not consider it possible to maintain them as distinct taxa. I recognise the 'P. loureiri complex' as one species, P. loureiri Kunth comprising two polymorphic varieties, var. loureiri and var. humilis (Becc.) S. Barrow. The nature and pattern of distribution of polymorphic characters is poorly known and it is unclear to what extent ecological factors play a role in determining intravarietal variation. More extensive sampling from a wide range of populations is required if further taxa are to be defined within the varieties of P. loureiri. However, the description of such intravarietal taxa would have ramifications on taxon delimitation elsewhere in the genus. It is my view that the polymorphism observed within the varieties of P. loureiri Kunth is equivalent to that included within the polymorphic African species, P. reclinata, within which I have not formally recognised infraspecific taxa. (Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae))A

Biology And Ecology

  • A variety of habitats from sea-level to 1700 m, in open scrublands or as part of the undergrowth of dry dipterocarp, mixed deciduous or pine forest. The species is very common in disturbed, anthropogenic areas such as seasonally-burnt grasslands, along roadsides or raised ground bordering rice-paddy. As with all species of the genus, staminate flowers of P. loureiri are visited by a range of insects, particularly beetles, but it is not known which are the pollinators and which are merely pollen thieves. The fruits are eaten by a range of birds and mammals attracted by the sweet but thin mesocarp. (Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae))A

Conservation

  • Phoenix loureiri is not considered to be threatened because it thrives in disturbed, anthropogenic areas. However, populations are declining in certain parts of their ranges. Padmanabhan & Sudhersan (1988) noted 'mass destruction' of the species on hillsides in southern India due to heavy pressure from harvesting for leaves. Gruezo & Fernando (1985) called for continued protection of the species in the Philippines, where it is found only in localised populations on Sabtang and Batanes Islands. (Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae))A

Uses

  • The leaflets of P. loureiri have many domestic uses, such as the manufacture of mats and brooms. In the Philippines shredded, sun-dried juvenile leaves are woven as raincoats (Gruezo & Fernando 1985). The apical bud is sweet and can be eaten as a vegetable (palm cabbage). The fruits are sweet, if a little mealy, and are commonly eaten by children. Padmanabhan & Sudhersan (1988) noted the medicinal use of the species by tribal people in southern India. (Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae))A

Description

  • Solitary or clustering palm. Stem to 1 - 4 (5) m, without leaf sheaths to c. 10 - 30 (40) cm in diam., with crowded diamond-shaped, persistent leaf-bases, internodes very short. Leaves to 2 m long; pseudopetiole 20 - 40 cm long; leaf sheath reddish- brown, fibrous; acanthophylls c. 15 on each side of rachis, yellow-green to orange, to 20 cm long; leaflets arranged in more than one plane of orientation, proximally fascicled in 3s - 4s, more regularly arranged apically, to 130 on each side of rachis, 20 - 45 x 0.5 - 2.3 cm, flaccid or stiff; lamina either concolorous or abaxial surface bluish-green with tannin in patches along midrib and continuous along leaflet margin. Staminate inflorescences erect; prophyll yellow-green in colour, to 40 x 7 cm (often much smaller); peduncle to c. 15 cm long; rachillae congested on rachis, c. 10 cm long. Staminate flowers sweet-scented initially, turning musty, with calyx a three- pointed cupule 1.5 - 2 mm high; petals yellow-white, oblong in shape, c. 4- 6 x 2 - 2.5 mm, with apex roughly undulate and often thickened; anthers yellow-white. Pistillate inflorescences erect, often arching with fruit maturity; prophyll papery to coriaceous, splitting twice either along or between margins, c. 20 x 3 cm; peduncle to 1.5 m long; rachillae up to 40 in number, to 40 cm long, elongating with fruit set. Pistillate flowers with calyx cupule 1.5 - 2 mm high, yellow; petals orange-pink to yellow, 2 - 2.5 x 3 - 4 mm. Fruit restricted to the distal half to two thirds of rachilla, ovoid to obovoid, 9 - 18 x 5 - 9 mm, maturing from green to blue-black when ripe, with mesocarp mealy and slightly sweet. Seed obovoid, 11 - 18 x 6 - 9 mm, with rounded ends, and raphe extending full length of seed; embryo lateral opposite raphe; endosperm homogeneous. (Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae))A

Bibliography

    A. Barrow, S.C. 1998: A Monograph of Phoenix L. (Palmae: Coryphoideae)