Manjekia maturbongsii (W.J. Baker & Heatubun) W.J. Baker & Heatubun, Kew Bull. 69: 9525 (2014)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Irian Jaya present (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A
Biak Island. (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Habitat

  • Lowland forest on limestone with thin soils and many sink holes, 80-170 m elevation. (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Diagnosis

  • Distinguished from other genera of subtribe Ptychospermatinae (tribe Areceae) by its moderately robust, solitary habit, arching leaves, broadly lanceolate pendulous leaflets with wide, concave, praemorse apices, white inflorescence axes and terete, straw-coloured endocarp with broad, adherent, longitudinal fibres interspersed with very fine fibres. (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Conservation

  • Endangered (Baker & Heatubun 2012). (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Etymology

  • The new generic name is based on Manjek, the local name in Biak dialect for this palm. The species epithet, coined previously (Baker & Heatubun 2012), honours Rudi Maturbongs, palm expert at Universitas Negeri Papua and first collector of herbarium specimens of the species. (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Common Name

  • Manjek (Biak dialect). (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Uses

  • The stems are used for flooring and pillars in traditional houses. (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Description

  • Solitary palm. Stem 10-15 m tall, 10-20 cm in diam., tapering towards apex, surface brown with white blotches, internodes 2 - cm apart. Leaves c. 10 in crown; sheath 60-70 cm long, crownshaft 80-90 × 10-12 cm; petiole 26-45 cm long, rachis 2.5-3 m long; leaflets 25-30 each side of the rachis, basal leaflets 32-50 cm long, 1-4.5 cm wide, sometimes with rein up to 1 m attached, middle leaflets 40-49 cm long, 9-12 cm wide, apical leaflets 6.5-42 cm long, 2-4.5 cm wide. Inflorescence 60-70 cm long; prophyll 24-26 cm long, 6-8 cm wide, greenish white, splitting apically, caducous later; first peduncular bract 31-35 × 5-7 cm, attached 15-20 mm above prophyll insertion; peduncle 8-14 cm long, 2-2.5 cm wide; primary branches 25-28, longest primary branch (basal-most) 40-65 cm; rachillae 8-19 cm long, 1.5-3.5 mm in diam., floral triads 3-9 mm apart. Staminate flower 6.5-8 mm long, 2.5 ? 3.2 mm in diam. in bud; sepals 2-2.4 mm long, c. 3 mm wide; petals 7-7.5 mm long, c. 3 mm wide; stamens 30-32, 4.5-6 mm long; filaments 1.5-4 mm long; anthers 3-3.8 mm long, 0.5-0.8 mm wide; pistillode c. 5 mm long, 1.2-1.4 mm in diam. Pistillate flower 4.5-5 mm long, c. 4.5 mm in diam.; sepals 3-4 mm long, 4-4.5 mm wide; petals 4-4.5 mm long, 3-3.5 mm wide; staminodes 2-3; gynoecium c. 4 mm long, c. 3 mm in diam. Fruit 24-31 mm long, 14-16 mm in diam.; pericarp 1.5-3 mm thick, endocarp 23-30 mm long, 12-12.5 mm in diam. Seed 14-20 mm long, 9.5-12 mm in diam, ellipsoid (Figs 4, 5). (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Materials Examined

  • INDONESIA. Papua Province, Biak Numfor Regency, Biak Island: forest on the road side, main road from North Biak Nature Reserve to Biak town, 0°44'20"S 135°52'57"E , 25 July 2009, Heatubun et al. 971 (holotype K!; isotypes BO!, FTG!, MAN!, NY!); North Biak Nature Reserve, Sansundi village, 0°42'S 135°50'E, 8 Sept. 1998, Maturbongs et al. 559 (BO!, K!, MAN!), Maturbongs et al. 560 (BO!, K!, MAN!); Samber forest, 1°8'33"S 135°53'43"E, 22 July 2009, Baker et al. 1336 (BO!, K!, FTG!, MAN!), 1°8'45"S 135°53'37"E, 22 July 2009, Baker et al. 1338 (BO!, K!, FTG!, MAN!); locality uncertain (given incorrectly on the label as Merauke district, but number sequence indicates the collector was active in Biak), 15 June 2001, Maturbongs et al. 686 (AAU!, BO!, FTG!, K!, MAN!). (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Notes

  • This palm is immediately recognised by its tall, elegant habit combined with its arching leaves with broad, pendulous, conspicuously praemorse leaflets and profusely branched greenish white inflorescences. Reports of a distinctive, undescribed species of Ptychospermatinae from Biak began to circulate during the 1990s (Zona 2000; Baker & Heatubun 2012). The first herbarium specimens were made by Rudi Maturbongs in 1998, although the material was at first overlooked at Kew as a robust form of Drymophloeus litigiosus (Becc.) H. E. Moore. Having observed it during a short visit to Biak in 2000, WB arranged an expedition to Biak in 2009 with CH to secure adequate material for morphological and molecular study. Manjekia maturbongsii was originally described in Adonidia (Baker & Heatubun 2012) based on molec ular phylogenetic evidence from two low-copy nuclear genes (Zona et al. 2011). Morphological similarities to the existing species of Adonidia, A. merrillii, were identified, such as the limestone habitat of both species, their white inflorescences branched up to four orders, the fruits with red epicarp, the endocarps with adhering pale, flattened, longitudinal fibres interspersed with finer fibres, and seeds with ruminate endosperm. However, differences between the two taxa were also highlighted by the authors (Baker & Heatubun 2012). Manjekia bears leaves with broad, pendulous leaflets in a single plane with wide, concave, praemorse tips, whereas leaflets of Adonidia are ascending, narrower and in slightly different planes with inconspicuously praemorse or bifid tips. In addition, the staminate flowers of Manjekia contain fewer stamens (30-32) than those of Adonidia (45-50). The latest molecular phylogenetic evidence (Alapetite et al. 2014) contradicts the earlier study (Zona et al. 2011) and most strongly indicates a sister relationship with Jailoloa, though one low-copy nuclear data partition (AG1) indicates an alternative, poorly supported placement as sister to Ponapea Becc. Compared to Jailoloa, Manjekia is more robust with very different leaflets (ascending, narrow, leathery leaflets in Jailoloa), more stamens per staminate (c. 16 in Jailoloa) and contrasting inflorescence morphology and fruit colour (purple inflorescences branched to three orders with orange-yellow fruit in Jailoloa). Manjekia differs from Ponapea in its elongate, lageniform pistillode (short and conical in Ponapea) and the terete seed with ruminate endosperm (seed ridged in Ponapea, or if terete then homogeneous endosperm). For further discussion of Manjekia in the context of the Biak palm flora see Baker & Heatubun (2012). (C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69)A

Bibliography

    A. C.D. Heatubun, Zona, S. & Baker, W.J. 2014: Three new genera of arecoid palm (Arecaceae) from eastern Malesia. – In: Kew Bulletin 69