Wallaceodoxa raja-ampat 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)
Only known from two of the Raja Ampat islands, Gag Island and Waigeo Island, off the western end of mainland New Guinea. (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

  • Distinguished from other genera of subtribe Ptychospermatinae (tribe Areceae) by its moderately robust, solitary habit, arching leaves, thick, white, lanate indumentum interspersed with large, brown-black twisted hairs on sheath, petiole and rachis, narrowly linear lanceolate pendulous leaflets with obliquely praemorse apices, white inflorescence axes, thick rachillae with rather crowded triads, short, irregularly ellipsoidal pistillode and rounded, strawcoloured endocarp with adherent, longitudinal fibres. (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 (CR B1ab(iii,v) + 2ab(iii,v); C1 + 2a(i); D). Wallaceodoxa raja-ampat is known from only two subpopulations, one in Gag Island and the other in Waigeo Island. In a census of the Gag subpopulation in 2006, 45 adults, 32 juveniles and 129 seedlings were recorded. In 2011, however, the same subpopulation consisted of only 28 adults and no juveniles or seedlings, due to land clearance by local people for slash-and-burn agriculture and the expansion of coconut plantation, representing a 38% decline in adults. The Waigeo subpopulation was discovered in 2011. A rapid survey within a 2 × 2 km area in the middle of the developing town of Waisai, the new capital of Raja Ampat Regency, located 5 adults, 63 juveniles and 378 seedlings. Although we have not been able to explore for further subpopulations elsewhere on Waigeo, we estimate that there are very few additional individuals to find because this taxon is restricted to the limestone forest in Waisai in the south of Waigeo. Thus, Wallaceodoxa raja-ampat meets the threshold for the extinction risk category Critically Endangered (IUCN 2012) on multiple criteria, primarily because of its small size of the total adult population, area of occupancy of 8 km2 (<10 km2), extent of occurrence of 66 km2 (<100 km2), observed and inferred population decline and the severe fragmentation of the two subpopulations, which are located on separate islands. The decline in habitat quality and its fragmentation are issues of grave concern for both subpopulations. In Gag Island, 75%of the island has been included in a nickel mining concession and the remainder of the island on limestone-rich soils has been largely converted to coconut plantation and traditional mixed-crop gardens. Only patchy rain forest remnants persist in the limestone part of the island. The Waigeo subpopulation is highly threatened by the development of Waisai. In fact, the entire area of occupancy for the Waigeo subpopulation lies within the town and will be Waisai's town centre in future. For example, the herbarium specimen from this site was collected at the local government office complex and town hall next to the Pari Convention Centre building. (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A

Etymology

Uses

Description

  • Solitary palm. Stem up to 30 m tall, 9-30 cm diam.; internodes with nodal scars inconspicuous, whitish brown. Leaves 11-19 in crown, 275-410 cm long including petiole; sheath tubular, 76-115 cm long and 16-30 cm wide, tapering to 10 cm wide; crownshaft 100-150 cm long; petiole 28-50 cm long, 2.5-3.5 cm wide and 1-1.5 cm thick at the base; leaflets 50-85 on each side of the rachis; basal leaflets 41-60 cm long, 0.5-2.5 cm wide, middle leaflets 70-114 cm long, 1-4.5 cm wide, apical leaflets 32-40 cm long, 0.5-1.5 cm wide. Inflorescence 50-100 cm long and 75-80 cm wide at anthesis; peduncle 15-20 cm long, 4-6 cm wide; prophyll 50-60 × 7-12 cm; peduncular bract similar to prophyll; primary branches up to 27 (including terminal rachilla), 33-50 cm long, 0.5-2.5 cmbetween branches; rachillae numerous, 11-18 cm long, 12-15 floral triads per 5 cm length of rachilla. Staminate flowers 7-7.5 × 2.5-mm in bud near anthesis, whitish creamto greenish white; sepals 3, free, 3.2-3.5 × 2.5? 3 mm; petals 3, united at the base, 6-6.3 × 3-3.5 mm; stamens 58-64, 3.5-5 mm long; filaments 2.5 ?3 × 0.3-0.4 mm, white; anthers 2-2.5 × 0.5-0.75 mm; pistillode 1-2 × 0.9-1.2 mm, 2-3 lobes, c. 0.5 mm deep, c. 0.3 wide, cream to brown. Pistillate flowers 5-6 × 3.5-4 mm near anthesis, cream to light green; sepals 3.3-5 × 3.5-7 mm; petals 5 × 6 mm, light green; staminodes 5-7, 0.4-1 × 0.2-0.3 mm; gynoecium 4-4.5 × 1.5 mm including stigma; ovule c. 1.5 × 0.8 mm. Fruit 17.5-20 × 10-12 mm, light green and turning yellow, orange and red when mature; pericarp c. 1 mm thick. Seed 10-12 × 9-9.5 mm; embryo 1.5-2.75 × 1-1.75 mm. (Figs 6, 7, 8). (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. West Papua Province, Raja Ampat Islands Regency: Gag Island, limestone forest near airstrip, 00°24'00.0"S 129°53'15.0"E, 26 July 2006,Heatubun et al. 741 (BO!, K!,MAN!,NY!, FTG!, BPK Manokwari!), Heatubun et al. 742 (BO!, K!, MAN!, FTG!, BPK Manokwari!); Gag Island, Kali Kablebet, 00°24'44.3"S 129°53'48.2"E, 28 July 2006, Heatubun et al. 746 (BO!, K!, MAN!); Waigeo Island, Waisai, Kelurahan Warmasen, behind Kantor Bupati, forest on right side of road to Pari Convention Centre Building (tanjakan gedung Pari), 15 April 2011, Heatubun et al. 1126 (holotype MAN!; isotypes 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

  • Wallaceodoxa raja-ampat is an impressive, solitary canopy palm that is recognised by its arching leaves with narrow, linear leaflets, the thick indumentum throughout the sheath, petiole and leaf rachis, and the white inflorescence, branched to three orders, with thick rachillae crowded with floral triads. It was discovered by the first author on Gag Island in 2006 (Heatubun et al. 2014) and is of grave conservation concern, both on Gag and Waigeo. Wallaceodoxa has been resolved as sister to Adonidia (Alapetite et al. 2014), but differs markedly from this species in the indumentum (thin grey indumentum in Adonidia), drooping leaflets in one plane with praemorse apices (ascending leaflets with acute bifid apices in Adonidia), the thick, congested rachillae (more slender with more widely spaced triads in Adonidia), the staminate flowers with 58 ? 64 stamens (45-50 in A. merrillii) and the ellipsoid pistillode (lageniform in Adonidia). As sister taxa,Wallaceodoxa and Adonidia represent a notable disjunction across Wallace's Line, the most important biogeographic boundary in the Malesian region (Baker & Couvreur 2012). (C.D. Heatubun, S. Zona & W.J. Baker - Three new genera of arecoid palm (Arecaceae) from eastern Malesia in Kew Bull.. 2014)A