Ceratolobus pseudoconcolor J.Dransf., Kew Bull. 34: 19 (1979)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Sumaterapresent (World Checklist of Arecaceae)B
Very local, extant in only two localities in hill forest at altitudes between 600 and 900 m in West Java and known from a third locality in the past, possibly also extant. Also known from one collection in South Sumatra. The known extant populations do not exceed 20 clumps in all and this species must be regarded as being endangered in Java. (J. Dransfield, A monograph of Ceratolobus (Palmae). 1979)A

Discussion

  • The first collection in Java made in 1871 by Scheffer from Sancang in Parahiangan (Preanger) was determined as Korthalsia, later as Ceratolobus glaucescens and then as C. concolor. Two features of the Javanese concolorous leafleted taxon immediately suggest this is not true C. concolor-viz. the ovoid fruit and seed, and the homogeneous endosperm-true C. concolor has a rounded fruit and seed and a ruminate endosperm. Furthermore at least some of the spiculae in C. concolor are grouped whereas the Javanese plant has scattered discrete spiculae. Two clumps of Ceratolobus sp. from the South Sumatra I Nature Reserve, at Karang Berak near Tanjung Cina, possibly belong here. Unfortunately the two specimens (Dransfield 1263 (BO, L) and Dransfield 1266 (BO)) do not bear ripe fruit. They were found in highly disturbed logged forest and were growing in full sunlight. Many features suggest they were juvenile stems (no cirrus, large spines and no or few spiculae as in C. pseudoconcolor in Java). The immensely long peduncles (over 50 cm long) bear numerous lateral spines, a feature ofsome stems ofC. pseudoconcolor in Java, and a feature which even when present in C. concolor, is very poorly developed-e.g. the tiny protrusions on the peduncle of the type of C. concolor. It is therefore more prob.able that the Tanjung Cina plants represent juvenile forms of C. pseudoconcolor than of C. concolor but more collections from this area are necessary before any satisfactory decision can be made. (J. Dransfield, A monograph of Ceratolobus (Palmae). 1979)A

Diagnosis

  • a speciebus ceteris Ceratolobi foliorum vaginis spiculatis, foliolis concoloribus, fructibus anguste ellipsoideis, endospermio homogeneo distinguendus; a C. glaucescente foliolis concoloribus vaginisque spiculatis et a C. concolore fructibus anguste ellip- soideis non rotundati et endospermio homogeneo differt. (J. Dransfield, A monograph of Ceratolobus (Palmae). 1979)A

Description

  • Slender clustering rattan rarely exceeding 10 m in height, usually much less, often already flowering when 1 m tall. Stems closely clustering by short suckers to 5 mm diam. without sheaths, to 10 mm with sheaths, internodes 15-22 cm long. Leaf sheaths pinky-grey-green when fresh and young, dull green when old and fresh, dull green-brown when dry, covered with caducous scurfy grey indumentum, chestnut and deep chocolate-coloured pseudoparenchymatous scales, and evenly scattered easily detached dark brown spiculate spines to 1.5 mm long, borne on slightly bulbous green bases, these last remaining long after the spiculae have become detached; geniculus prominent, armed as the rest of the sheath; juvenile sheaths espiculate, armed with pale brown spines to 1.5 cm long. Juvenile leaves with long petioles to 18 cm or more, 4 mm diam. and no cirri; adult leaves with petioles rarely exceeding 5 cm, often petiole almost absent, armed with spiculae and caducous indumentum; whole leaf to 1 m including cirrus 30-50 cm long: rachis armed with reflexed, pale-green, black-tipped spines to 2 mm long, c. 2.5 cm distant below, decreasing above, intergrading with reflexed, grouped, grapnel hooks on the cirrus where 0.5-1.5 cm distant. Leaflets 6-8 on each side of the rachis, 12-23 x 4-6 cm at the widest point, rather markedly plicate, dark green above, only slightly paler below, without dense white indumentum, rhomboid with a moderately well-defined apical portion to 3 x 0.5 cm at the base, scattered bands of caducous scales occurring on the upper surface; longest leaflets the second or third pair from the base, decreasing in size distally, ± regularly arranged, ± alternate; lower leaf margins unarmed with scattered bristles along the upper praemorse margins; main veins 15-28 radiating from the leaflet base; transverse veinlets moderately prominent above and below. Emerging leaf pink, rapidly turning dull brown then green. Inflorescences staminate and pistillate on separate plants, superficially similar, pendulous on a slender peduncle, 15-25 cm x 1 mm, the peduncle unarmed or with a row of narrow prickles 1-5 mm long, up to 10 mm distant (on either side); peduncle adnate to the sheath of the leaf above the subtending leaf. Prophyll pale pinky-green at first, later green, then drying to cinnamon-brown at anthesis with scattered whitish indumentum and dark brown scales, 12-20 x 1-2.2 cm, rather gradually tapering to the beak, up to 2.5 cm x 3 mm, unarmed; apical slits to 15 x 1 mm. Axis branching to 2 orders with up to 5 first-order branches. First-order bracts tightly sheathing to 0.5 mm high with apiculus to 4 mm or more. Staminate flowers solitary, creamy-yellow at anthesis, borne on an alveolus c. 0.5 mm diam.; calyx with lobes c. 1 mm long, triangular; corolla c. 4 mm long, split ± to the base into 3 petals c. 2 mm wide near the base, tapering to triangular tips; stamens 6; filaments c. 0.5 mm long; anthers 1.5 x 0.7 mm, canary yellow; pistillode c. 0.5 mm long, trifid. Pistillate flower borne with sterile staminate flower on an alveolus c. 1 mm diam.; calyx with 3 triangular lobes c. 5 mm long; corolla c. 4 mm long, split to I length into 3 triangular lobes; staminodes with broad tri- angular bases and subulate empty anthers to 1.2 mm long in all; ovary c. 2 mm diam., ovoid, tipped with 3 sinuous stigmas to 1.2 mm long. Sterile staminate flower c. 4 mm long; calyx 0.7 mm long, shallowly lobed; corolla c. 4 mm long, split to near the base into 3 petals each 1.2 mm wide; staminodes c. 2 x 0.25 mm. Mature fruit narrowly ellipsoidal, up to 1.4 cm long by 0-7 cm diam., covered with 12 vertical rows of chestnut-brown scales with pale edges, and tipped with remains of the stigmas. Seed covered by a thin sarcotesta, somewhat sinuous-grooved longitudinally, up to 1.2 X 0.5 cm, flattened on one side, with a narrow groove running along the length of the diaspore. Endosperm homogeneous; embryo basal. Germination adjacent-ligular; eophyll with four faintly praemorse fanned leaflets. (J. Dransfield, A monograph of Ceratolobus (Palmae). 1979)A

Materials Examined

  • SUMATRA. Palembang: Lematang Ulu, Grasshof 189 (BO, FI). JAVA. West Java: Parahiangan, Sancang, 1871, Scheffer s.n. (BO). Sukabumi, Lengkong: Dransfield 1035 (holotype BO; isotypes K, L), 1700 (cult. in Hort. Bogor.) 1719 (L), 1720 (BO), 2478 (BO) 2484 (BO), 2495 (cult. in Hort. Bogor.) 3905 (cult. in Hort. Bogor.), 4762 (BO) and 4764 (cult. in Hort. Kew). Cianjur, Sukanagara, Gunung Karang, Dransfield 3911 (BO). (J. Dransfield, A monograph of Ceratolobus (Palmae). 1979)A