Rhopaloblaste augusta (Kurz) H.E.Moore, Principes 14: 79 (1970)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Nicobar Is. present (World Checklist of Arecaceae)B
Known only from the Nicobar Islands, being more common in the northern islands according to Kurz (1875). Now cultivated quite widely throughout South East Asia and elsewhere. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Discussion

  • NICOBAR ISLANDS. Camorta [Kamorta]: Feb. 1875, Kurz s.n. (CAL, K!, type). Car Nicobar: Near Headquarters, Nov. 1975, Nair 2294 (L!). CULTIVATED. Indonesia, Java, Bogor Botanic Gardens, May 1936, Furtado SFN 30946 (BH, K!). (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Biology And Ecology

  • Lowland rain forest. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Conservation

  • Data deficient. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Common Name

  • Not known. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Uses

  • Of all the species of Rhopaloblaste, R. augusta is perhaps the most widely grown species for ornamental purposes. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Description

  • Robust, mid-storey, solitary palm bearing up to 11 leaves in the crown. Stem to 25 m tall, 20 - 30 cm diam., surface brown, becoming grey with age, leaf scars conspicuous. Leaf sheath 48 - 60 cm long, greyish brown, lepidote tomentose; crownshaft 50 - 61 cm long, 30 - 40 cm diam.; petiole short, 8 - 10 cm long, concave on adaxial and rounded abaxially; rachis 2 - 4 m long, with dense interlocking pale whitish brown scales on the abaxial surface especially when young, but becoming brownish black with age, less dense whitish brown scales on the adaxial surface; leaflets 90 - 100 each side of rachis, borne 3.5 - 4 cm apart, in one plane, pendulous, middle leaflet 60 - 70 x 2 - 3 cm, sublinear, acuminate, tapering acutely and bifid at the apex, discolorous, with sparse ramenta present along the mid-veins of the pinnae on the abaxial surface, and with rusty dark brown membranous scales on the adaxial surface, persisting at the base of the pinnae. Inflorescence 40 - 60 cm long, branched to 3 orders, primary branches 14 - 16, 45 - 56 cm long, basal pair of primary branches strongly recurved; prophyll 40 - 45 cm long, with sparse greyish brown scales; peduncle 4 - 5 cm long; rachillae moderately slender, 36 - 43 cm long, 2.9 - 3.8 mm diam., dull greenish brown. Staminate flower symmetric, 6 - 6.8 mm long, 4 -4.8 mm diam.; sepals 2.5 - 3 x 2.6 - 2.8 mm, strongly imbricate, rounded; petals 4 - 4.5 x 3 - 3.5 mm, broadly elliptic; stamens 3.2 - 3.5 mm long, filaments 2 - 2.1 mm long, connate at the base, anthers 3 - 3.2 mm long, 0.8 - 1 mm diam.; pistillode conical, 4.3 - 4.5 mm long, 1 - 1.1 mm diam. at the base. Pistillate flower 4 - 4.1 mm long, 3.8 - 4 mm diam., borne throughout the rachillae; sepals 3.5 - 3.8 x 3 - 3.5 mm, rounded, margin on the apex serrate; petals 3.6 - 4 x 2.8 - 3 mm, broadly elliptic; staminodes 4, lobes 0.8 -1 x 0.9 - 1 mm, acute at the apex; gynoecium 2.8 - 3.1 mm long, 1.2 - 1.5 mm diam., ovoid. Fruit 22 - 26 mm long, 10 - 14 mm diam., elongate ellipsoid, orange to red when ripe; cupule of persistent perianth 7 - 8 mm long. Seed 17 - 20 mm long, 9 - 11 mm diam., elongate-ellipsoid, brownish, with a conspicuous impression over the hilum; testa brown. (Banka, R. & Baker, W.J. 2004: A Monograph of the Genus Rhopaloblaste (Arecaceae))A

Materials Examined

  • R. augusta is distinct in its medium-sized, elongate, ellipsoid fruits, moderately slender fruit- bearing rachillae and inflorescences branched to three orders. It is a promising ornamental species, grown in botanical gardens for its bright fruits and attractive foliage. (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