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

Primary tabs

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
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

Diagnosis

Conservation

Etymology

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

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