Jailoloa halmaherensis (Heatubun) Heatubun & W. J. Baker, Kew Bull. 69: 9525 (2014)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Malukupresent (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A
Known only from the type locality in East Halmahera, North Moluccas, Indonesia. (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Habitat

  • Very steep terrain (more than 45°) on rocky outcrops or very poor soils in ultramafic heath forest at an elevation of 530-550 m above sea level. As noted by Heatubun (2011), this taxon appears to be adapted to the extreme conditions of ultramafic geology and soils that are thin or even absent. The ultramafic rocks have produced extremely weathered oxisol soils that are reddish yellow due to the high concentration of iron, magnesium and other metals, including nickel. (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Diagnosis

  • Distinguished from other genera of subtribe Ptychospermatinae (tribe Areceae) by its slender, solitary habit, recurved leaves with ascending, narrow, leathery leaflets, inflorescence axes and flowers purple at anthesis, stamens c. 16, fruit orange-yellow when ripe with purple perianth cupule, thin, terete, straw-coloured endocarp with fine, longitudinal fibres, and the terete seed. (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Conservation

  • Critically Endangered (see Heatubun 2011).
    The conservation status of this taxon, which has been assessed as Critically Endangered, is further accentuated by its new status as a monotypic genus. The future survival of this palm is a serious cause for concern. For further discussion see Heatubun (2011). (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Common Name

  • None recorded. (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Etymology

  • The new generic name refers to Jailolo (sometimes spelled Gilolo), the native name of Halmahera Island, that was formerly widely used (e.g. Wallace 1869). (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Uses

  • None recorded. (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Description

  • Solitary palm. Stem up to 12 m tall, 5-7 cm diam.; internodes 5-7 cm long, nodal scars conspicuous, dark brown. Leaves c. 9 in crown, 190-200 cm long including petiole; sheath tubular, 40-50 cm long and about 15 cm wide, tapering to 8 cm wide, greenish brown; crownshaft up to 75 cm long; petiole 22-23 cm long, about 2 cm wide and 1.1 cm thick at the base; rachis arching; leaflets 25-26 on each side of the rachis; basal leaflets 55-75 cm long, 2.5 cm wide, pendulous rein up to 27 cm long, middle leaflets 44-48 cm long, 3.5-4 cm wide, apical leaflets 12.5-15 cm long, 0.3-1.2 cm wide; ramenta up to 3.5 cm long, 0.5 cm wide. Inflorescence up to 65 cm long at anthesis, with 18-20 primary branches including terminal rachilla; peduncle 10-15 cm long; prophyll c. 20 × 4 cm; complete peduncular bract c. 30 × 3 cm; the first order branches 35-45 cm long, about 10-13 branches (including terminal rachilla), 1-7 cm between branches; rachillae numerous, 7-12 cm long, each bearing 8-15 floral triads. Staminate flowers 5.5 × 2 mm in bud near anthesis, purple; sepals 3, free, c. 2.2 × 2 mm; petals 3, c. 4.5 × 2 mm; stamens c. 16, 2.5-4 mm long; filaments 1.75-2 mm long, dark brown; anthers 2.5-3 mm long; pistillode c. 2.5 × 0.1 mm. Pistillate flowers 6.5 × 6 mm at anthesis, purple; sepals 3.5 × 3.5 mm; petals 5 × 4 mm, purple with a thin line along the margin; staminodes inconspicuous; gynoecium 4.5 × 2.5 mm including stigma; ovule basal. Fruit 13-15 × 10 × 10 mm, epicarp purple when juvenile, becoming bright yellow or light orange when mature; pericarp c. 0.5 mm thick. Seed 10 × 8.5 × 7 mm; hilum up to 3 mm wide, embryo 2.5 × 1 mm (Figs 2, 3). (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Materials Examined

  • INDONESIA. North Moluccas Province, Halmahera Timur Regency: Maba Town, PT. Buena Persada (Solway International) Nickel Mining Concession Area, Gunung Batu, path way back from camp D to the main camp, 00°42'50.6"N 128°06'02.6"E, 25 Feb. 2011, Heatubun 1125 (holotype MAN!; isotype BO!, K!). (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Notes

  • Jailoloa halmaherensis is a slim, solitary palm bearing strongly arching leaves with narrow, leathery, ascending leaflets. It was discovered in Halmahera in 2011 by the first author, who described it in Ptychosperma (Heatubun 2011), assigning it to subgenus Ptychosperma (sensu Essig 1978). However, the molecular phylogenetic evidence of Alapetite et al. (2014) leaves little doubt that its placement in Ptychosperma is incorrect. Although Jailoloa and Ptychosperma are superficially similar as slender palms with colourful inflorescences, important morphological differences can be observed. As already noted by Heatubun (2011), Jailoloa differs from Ptychosperma in the endocarp and seed being rounded and terete in cross section, whereas all species of Ptychosperma bear endocarps and seeds that are lobed or angled, even if obscurely so (Essig 1978; Zona 1999). The combination of purple inflorescence axes and yellow-orange fruit colour is also not found in Ptychosperma, in which orange fruit are found only in species with green or yellow inflorescences axes (Essig 1978). Ptychosperma also never has ascending leaflets. The total evidence phylogenetic analysis of Alapetite et al. (2014) resolved Jailoloa as sister to Manjekia (syn. Adonidia maturbongsii), but some data partitions (PRK, ndhA) provided evidence for a sister relationship to Normanbya F. Muell. ex Becc. when analysed separately. Jailoloa differs from Manjekia in its slender habit (moderately robust in Manjekia), ascending, leathery leaflets (pendulous, non-leathery, broadly lanceolate leaflets in Manjekia), inflorescence and fruit colour (white with red fruit in Manjekia), and number of stamens (30-32 in Manjekia). It differs from Normanbya in size (moderately robust in Normanbya), leaflets (subdivided and plumosely arranged in Normanbya) and inflorescence colour (green in Normanbya). Jailoloa halmaherensis is a very rare palm, with a small population known only from ultramafic heath forest at a single site that falls within a nickel mining concession (Heatubun 2011). (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Bibliography

A. C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014