Rhopaloblaste ceramica (Miq.) Burret, Repert. Spec. Nov. Regni Veg. 24: 288 (1928)

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Content

Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Maluku present (World Checklist of Arecaceae)B
New Guinea present (World Checklist of Arecaceae)B
Widespread from Halmahera and Buru in the Moluccas through to Ceram, then to mainland New Guinea. In Papua New Guinea, known only with certainty from Sandaun and East Sepik Provinces in the north-western part of the country. However, the lost type of the dubious synonym R. dyscrita originates from Morobe Province in the east. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Discussion

  • Rhopaloblaste ceramica is the largest of all the species in the genus and is easily distinguished by its large asymmetrical fruits with a substantial cupule of persistent perianth, and the inflorescence branched to three orders with very robust rachillae. Rhopaloblaste ceramica was the first of the species of Rhopaloblaste to be described, based on material collected in 1860 by Teijsmann and de Vriese from Ceram in the Moluccas. Miquel originally placed it in the genus Bentinckia as B. ceramica Miq. Ten years later it was moved to Cyrtostachys (C. ceramica (Miq.) H. Wendl.). In describing the genus Rhopaloblaste in 1876, Scheffer named R. hexandra based on cultivated material in Bogor Botanic Garden that allegedly originated from Bacan, also in the Moluccas. Beccari (1885, Martelli 1935) considered R. hexandra and B. ceramica as synonymous, a conclusion that was accepted by Burret (1928), who was responsible for combining the earlier epithet with Scheffer's genus Rhopaloblaste, and Moore (1970). An old specimen, annotated as R. hexandra and said to be from Bacan, but lacking a date, is in the Bogor herbarium. It cannot be interpreted as the type because Scheffer did not refer to the material in the protologue and there is inadequate information on the specimen for us to infer that he had access to it. However, the placement of R. hexandra in synonymy with R. ceramica cannot be disputed on account of the excellent photograph and diagnostic plate published with the protologue. In the absence of original material, the diagnostic plate is designated as lectotype here. Subsequently, Burret (1940) described R. micrantha based on two collections from Morobe Province, Papua New Guinea, Clemens 7987 from Kalasa and Clemens 8297 (type) from Boana. These specimens were presumably destroyed in Berlin and duplicates have not been located. Moore (1970) recognised that R. micrantha Burret was a later homonym of Rhopaloblaste micrantha (Becc.) Hook. f. ex B. D. Jacks. (=Ptychosperma micranthum Becc.) and accordingly published a new name R. dyscrita H. E. Moore (dyskritos = doubtful). He was unable to link the concept to any earlier name because authentic material of the Clemens collection was not available and he was unable to match Burret's description with the species that he knew. Burret's protologue of R. dyscrita, as R. micrantha Burret, suggests that it closely resembled R. ceramica, differing only in its spreading pinnae and smaller staminate flowers. After examining the material of R. ceramica, including recent collections made since the publication of Moore's work, and comparing it with the description of R. dyscrita, we are tentatively placing R. dyscrita in synonymy with R. ceramica, because both have large fruits and robust inflorescences branching to three orders. If this synonymy proves to be correct, it dramatically alters the distribution pattern of the species as understood from material named with certainty, extending its range considerably to the east. New material is required from the type locality of the Clemens collections to confirm this decision. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Biology And Ecology

  • Well drained lowland to lower montane primary rain forests. In secondary rain forests it is found in old garden areas, on broken coral to deep, loose, porous, black volcanic soil. Also on alluvial flats in deep clay soil. From 35 to 900 m above sea level. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Conservation

  • Least concern. Though often infrequent, R. ceramica is widespread and cannot be considered threatened. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Common Name

  • Ahad (Buru dialect), Henahena (Ternate dialect), Ogulubenge (Tobaro dialect, Akelamo Oba, Maluku). (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Uses

  • The shoot apex is edible. The wood is used for arrowheads and floorboards for houses. Occasionally cultivated as an ornamental. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Description

  • Robust canopy solitary palm bearing up to 15 - 17 leaves in the crown. Stem to 35 m tall, 15 - 29(- 35) cm diam.; surface slightly rough, brownish grey leaf scars prominent; internodes 12 - 14 cm basally, decreasing to 1 cm distally. Leaf sheath 1.2 - 1.5 m long, pale brownish white, moderately to densely lepidote- tomentose; crownshaft 1.3 - 1.5 m long, c. 25 - 40 cm wide, dull-green; petiole 3.5 - 4.5 cm long, shallowly concave on adaxial surface; rachis 3 - 4 m long, with abundant matted dark brown scales on adaxial surface, densely lepidote-tomentose on the abaxial surface, becoming brownish with age; leaflets 111 - 120 each side of rachis, 2.5 - 3 cm apart, in one plane, pendulous, middle leaflet 100 - 112 x 2.3 - 2.5 cm, linear, tapering acutely and bifid at the apex, adaxial surface dark green with dark brown twisted scales near the base of the pinnae and along adaxial surface of midrib, abaxial surface dull green and with some lepidote tomentum. Inflorescence massive, 55 - 130 cm long, with a spread of 1 - 1.5 m, divaricate, branched to 3 orders, primary branches 16, 45 - 75 cm long, with basal pair of primary branches strongly recurved; prophyll 65 - 70 x 10 - 18 cm, dark green, with dense greyish brown indumentum; peduncle 8 - 10 cm long, 7- 10 cm diam., greyish with some tomentum; robust rachillae 45 - 75 cm long, 4.9 - 7.3 mm in diameter, greyish green; flowers sunken in shallow pits formed by rachilla bracts. Staminate flower symmetric, greenish, 6.5 - 7 mm long, 6.5 - 6.8 mm diam. at anthesis; sepals 3 - 3.1 x 3.1 - 3.3 mm, broadly elliptic; petals 6 -6.5 x 6.5 - 6.7 mm, broadly elliptic, glabrous; stamens 3.3- 4 mm long, filaments 2- 2.5 mm long, connate at the base, yellowish, anthers 2.1 - 2.3 mm long, 0.9 - 1 mm diam., elliptic; pistillode conical, 2.3 - 2.5 mm long, 1.2 - 1.3 mm diam. Pistillate flower slightly asymmetric, 4.3 - 4.7 mm long, 7.6 - 7.9 mm diam., borne throughout the rachillae; sepals 3.9 - 4 x 3.7 - 3.8 mm, rounded; petals 4.3 - 4.4 x 2.2 - 2.4 mm, elliptic; staminodes usually 4, lobes 0.8 - 0.9 x 0.7 - 0.8 mm; gynoecium 4.3 - 4.9 mm long, 4.2 - 4.5 diam., ovoid. Fruit 30 - 35 mm long, 16 - 18 mm diam., asymmetric ellipsoid-ovoid, yellow when immature, becoming red at maturity; cupule of persistent perianth 11 - 12 mm long. Seed 21 - 31 mm long, 14 - 16 mm diam., ellipsoid-ovoid, brown; conspicuous impression over the hilum, testa brown. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Materials Examined

  • INDONESIA, MALUKU. Ceram: 1860, Teijsmann & de Vriese s.n., (L!, BO, type). Halmahera: Central Halmahera, Akelamo Oba, Dec. 1974, de Vogel 4405 (K!, L!); Ekor, Kali Dowora Ina, Sept. 1974, de Vogel 3231 (K!, L!); Gunung Jailolo, Oct. 1974, de Vogel 3365 (K!, L!); 20 km SE of Dodinga, Darco/Modul Logging Camp, Tapayo, Sept. 1985, Sidiyasa et al. TCW 3683 (K!, L!). Burn: West Buru, Wae Nibe Wood Industry Base Camp 2, 20 km from Wae Ili, Nov. 1984, Mogea & Ismael 5145 (BO, K!); West Buru, Bara R., Duna Base Camp 8, Nov. 1984, Mogea & Jsmael 5364 (BO, L!, K!). INDONESIA, PAPUA. Manokwari Regency: Nuni, Sungai Asai, Aug. 1995, DransfieldJD 7582 (BO, K!, MAN), DransfieldJD 7583 (BO, K!, MAN). Jayapura Regency: North Cyclops Mts, Feb. 2001, Desianto 17 (AAU, K!, MAN); Arso Distr., Debemte, Tami R., March 2002, Gusbager 19 (K!, MAN, LAE). PAPUA NEW GUINEA. E Sepik: Yava Namba, Nov. 1996, Barfod et al. 379 (AAU, K!, LAE!). Sandaun Province: Vanimo, Black Water Creek Logging Area, Sept. 1982, Kerenga LAE 56484 (LAE!, L!); Along road between Vanimo & West Papuan Border, Nov. 1971, Essig LAE 55074 (LAE!); 2 miles from Lumi on road to Fatima, Nov. 1971, Essig LAE 55101 (LAE!); 1 mile from Lumi on road to Fatima, Nov. 1971, Essig LAE 55102 (LAE!); Miwaute, Nov. 1996, Barfod et al. 384 (AAU, K!, LAE!). CULTIVATED. Indonesia, Java, Bogor Botanic Garden, May 1903, Schoute s.n. (L!); Singapore Botanic Garden, Lawn D, Oct. 1929, Nur s.n. (K!, SING). (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Bibliography

    A. Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae)
    B. World Checklist of Arecaceae