Phoenix acaulis Roxb., Pl. Coromandel 3: 69 (1820)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Assampresent (World Checklist of Arecaceae)B
China Southeastpresent (World Checklist of Arecaceae)B
Indiapresent (World Checklist of Arecaceae)B
Nepalpresent (World Checklist of Arecaceae)B
West Himalayapresent (World Checklist of Arecaceae)B
Sub-Himalayan belt of northern India and Nepal. Griffith (1845) and Kurz (1877) recorded the species in Myanmar, but I have seen no specimens to support this. (S.C. Barrow, A Monograph of Phoenix L. (Palmae: Coryphoideae). 1998)A

Discussion

  • There has been widespread misapplication of the name P. acaulis, as a result of confusion of the species with stemless individuals of P. loureiri. The presence of a stem can be a misleading character in the genus because individuals of several species remain stemless for extensive periods before a trunk develops. Environmental factors have an important role to play; it is common for populations of P. loureiri in dry or disturbed areas to consist only of stemless, shrubby individuals, whereas populations occurring in less stressful conditions consist of palms with well-developed trunks. Differentiation between the two species is especially difficult when sterile. Even when in staminate flower, the prophylls of both species split to reveal inflorescences at ground level. The difference between the taxa becomes apparent on fruit set: the fruiting peduncle of P. loureiri elongating greatly to present mature fruit beyond the leaves, whereas that of P. acaulis remains at ground level, nested amongst the leaf bases (Noltie 1994). Pistillate rachillae of P. acaulis are distinctly shorter, thicker and more congested with larger fruit than those of P. loureiri. Each fruit of P. acaulis is subtended by a thickening of the rachilla, referred to by Roxburgh (1832) as a 'bractiform notch'. (S.C. Barrow, A Monograph of Phoenix L. (Palmae: Coryphoideae). 1998)A

Biology And Ecology

  • Griffith (1845) noted that P. acaulis grows in clay soil on elevated plains north of the Ganges river. The species occurs in open forest, scrublands, savannahs and pine forest understorey at 400 - 1500 m. In India P. acaulis flowers in the cold season from November to January with fruits ripening from April to June. (S.C. Barrow, A Monograph of Phoenix L. (Palmae: Coryphoideae). 1998)A

Conservation

  • The current distribution and conservation status of P. acaulis is unclear. During fieldwork in India for this study I failed to find and observe P. acaulis in its native habitat in Uttar Pradesh, despite visits to previous collection localities. However, the species has been reported, and recently collected, from Chitwan National Park in central Nepal, near the Indian border, and Dhar (1998) discusses the recent discovery of a population in Uttar Pradesh. It is assumed that, with the decline in forest habitats formerly ranging across the sub-Himalayan belt of northern India, the natural habitat for P. acaulis has suffered and the species is now restricted to more remote and inaccessible areas. A further threat to the species in some parts of its range has been the destructive harvest of the stem pith as a sago substitute. The bitter pith of P. acaulis was used heavily in India during a severe famine in the 1930's (Blatter 1926). (S.C. Barrow, A Monograph of Phoenix L. (Palmae: Coryphoideae). 1998)A

Common Name

Uses

Description

  • Acaulous palm; stem bulbous, to 10 cm high, densely covered with persistent leaf base stumps. Leaves 0.6 - 1.8 m long; leaf sheath reddish-brown, fibrous; rachis 0.3 - 1.5 m long x 1.5 - 2 cm in diam. at base; acanthophylls closely arranged in more than one plane, to 9 cm long; leaflets arranged in sub-opposite groups of 4s - 5s in more than one plane or orientation, c. 16 - 24 on each side of rachis, linear, 8 - 36 x 0.5 - 1.4 cm, flaccid, with strong marginal nerves; lamina concolorous, pale green. Inflorescences held at ground level. Staminate inflorescences not extending beyond prophyll; prophyll papery and splitting in many places, 13 x 2 cm; peduncle c. 7 x 0.6 cm; rachillae arranged in one whorl, 10 - 15 in number, c. 8 cm long. Staminate flowers not seen. Pistillate inflorescences not extending beyond prophyll; prophyll papery, c. 25 x 4- 6 cm; peduncle c. 9 - 12 x 1.4 cm, not extending on fruit maturity; rachillae arranged in one compact whorl, 15 - 20 in number, 4 - 14 cm, drying striate, with differential maturation of fruit along rachillae. Pistillate flowers c. 5 - 20 per rachilla, congested in arrangement, each subtended by a distinct rachilla swelling (bractiform notch), 3 - 10 mm long; calyx cupule 3 mm high; petals 5 - 6 x 4 mm. Fruit obovoid, 12 - 18 x 8 mm, ripening from green with scarlet apices to blue-black, with mesocarp scarcely fleshy and stigmatic remains prominently pointed (1 - 2 mm long). Seed elongate in shape, 10 x 5 mm, with rounded apices; embryo lateral opposite raphe; endosperm homogeneous. (S.C. Barrow, A Monograph of Phoenix L. (Palmae: Coryphoideae). 1998)A

Materials Examined

  • INDIA: ASSAM. Khasia Hills, Jan. 1886 (stam., pist.), Mann s.n. (FI-B!, K!). UTTAR PRADESH. Rishikhund, 3 April 1811 (stam., pist.), Buchanan-Hamilton 2199 (E!); between Saharanpur and Najiiabad in Bijnor, 10 March 1887 (pist.), Duthie s.n. (DD!, K!); Mailani, between Lakimpur and Kheri, 20 April 1964 (pist.), Malhotra 31498 (BSD!); Corbett National Park, Dubriya Chaur, 25 April 1971 (pist.), Pant 43751 (BSD!); Chamoli Distr., Nigol Valley, 1500 m alt., 17 Feb. 1979 (pist.), Naithani 63743 (BSD!). NEPAL. Kamali Valley, between Badalhot and Sika, 1350 m alt., 24 April 1952 (pist.), Polunin et al. 3967 (BM!, E!); Chitwan National Park, South Meghauli, 200 m alt., 7 March 1996 (pist.), Watson 9615 (E!). (S.C. Barrow, A Monograph of Phoenix L. (Palmae: Coryphoideae). 1998)A