Ceratolobus glaucescens Blume, Syst. Veg. 7: 1334 (1830)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Jawa present (World Checklist of Arecaceae)B
Thailand present (World Checklist of Arecaceae)B
Extremely rare and endangered, now only known from one locality in West Java where the population consists of less than thirty clumps. In highly disturbed coastal forest on a sandbar, and on a rocky hillslope nearby. (In the past apparently more widespread). (Dransfield, J. 1979: A monograph of Ceratolobus (Palmae))A

Discussion

  • There appears to be little variation within Ceratolobus glaucescens apart from slight differences in size, even between populations from different localities. In the wild, the only known extant population is in the much-degraded nature reserve of Sukawayana near Pelabuan Ratu where the population consists probably of less than 30 plants; the existence of this species in the wild must be considered as endangered with extinction. It is possible that it may be more widespread in forest fragments along the shores of Telok Pelabuan Ratu (Wijnkoops Bay). Cultivation is apparently easy and several recent attempts have been made to distribute it to Botanic Gardens throughout the world. In Kebun Raya, Bogor, seed sown in 1971 came into flower at about 1 m high in late 1973 and early 1974. Blume records the endosperm of C. glaucescens as being ruminate, but ripe fruit was apparently unknown to him. It is perhaps significant that Blume's description of the seed of C. concolor of which ripe fruits were available, is very detailed, giving a precise description of the ruminations, whereas that of C. glaucescens simply states endosperm ruminate. It seems most likely that Blume recorded the endosperm of C. glaucescens without ever having verified this, by extrapolation from C. concolor. NOMENCLATURAL NOTE. Merrill (1916) has made an attempt to account for as many plants as possible in Osbeck's 'Dagboek 6fwer en Ostindsk Resa' of 1757. When Osbeck visited Java, on one occasion (9 January 1752) he landed at Nieuw Baai (New Bay, that is the bay and strait between what is now called Pulau Peucang and the mainland of Ujung Kulon, the famous nature reserve). He described the presence of a spiny bipinnate palm with slender stems which formed a barrier preventing him from penetrating the forest without ripping his clothes and even his skin. He named the palm Caryota javanica but mentioned that he was not certain that it was correctly placed in Caryota. He described the plant as follows (from English Translation by Forster): 'Thefrondes are, as in Caryota bipinnated and whitish below: the leaves are opposite, almost oval, plicated; the upper margin as it were lacerated: the petioli are covered with many opposite, hamated spines, not only at the beginning of the foliola but even at the second and third pair of them'. Fructifications were absent. There are of course no known spiny Caryota spp. nor any with leaflets whitish below, and Merrill suggests that Osbeck encountered a rattan with fish-tailed leaflets-simply-pinnate, not double-pinnate as described by Osbeck who may have written doubly-pinnate to make the plant conform with the genus Caryota. Certainly Osbeck's description is of a rattan rather than of a Caryota. Merrill reasons that because Korthalsia is recorded as doubtfully present in Java and at any rate a mountain plant, Caryota javanica must indeed be Ceratolobus glaucescens which is a lowland plant recorded from the western part of Java. On this very tenuously based argument, Merrill includes Ceratolobus glaucescens under synonymy with Ceratolobus javanicus (Osbeck) Merrill. Merrill's supposition, however, is false because there is a species of Korthalsia in the lowlands of western Java, the widespread K. teysmannii. The other Javanese species of the genus, K. junghuhnii Miq., however, is a very local hill or montane species of West Java. KI. teysmannii is in fact very abundant at Ujung Kulon, and, just as Osbeck describes, forms in places a barrier of thorns which 'tore our cloaths, nay even the skin off our hands and faces' at the present day. Ceratolobus glaucescens is absent from Ujung Kulon as far as is known. It is therefore much more likely that Caryota javanica is a species of Korthalsia rather than a Ceratolobus. This being so, I reinstate Cerato- lobus glaucescens as the correct name for the lowland West Javanese taxon first described by Blume under this name, and would prefer to disregard completely the name Caryota javanica as being ambiguously based. (Dransfield, J. 1979: A monograph of Ceratolobus (Palmae))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, eventually forming small thickets, 5-8 mm diam. without sheaths, 8-13 mm diam. with sheaths; internodes 12-20 cm long. Leaf sheaths dull mid-green when fresh, pale brown when dry, covered with caducous flocculent, pale grey indumentum and scattered, dark, chocolate-coloured pseudoparenchymatous scales when young and densely armed with grey- brown yellowish-green-based horizontal spines, rather evenly distributed, sometimes sub-whorled, 2-20 mm long, stiff, not easily detached, generally rather broad-based, not spiculate; geniculus moderately prominent, armed as the rest of the sheath; ocrea minute, inconspicuous; spines around leaf sheath mouth rather denser and longer than those on the rest of the sheath, generally upward-pointing. Leaf 70-110 cm long including the terminal cirrus; petiole 5-12 cm long, short in plants exposed to full light, longer in shade plants, to 5 mm diam. at the base, rounded or flattened in cross-section above, armed as is the rachis with scattered, rarely paired, persistent spines 1-4 mm long, and remote solitary reflexed spines to 1 cm below, these last intergrading with short, reflexed grouped spines on the cirrus above; cirrus to 40 cm long, rarely more, the reflexed spine groups c. 1.5 cm distant below, decreasing to 0.5 cm distant above. Leaflets 6-8 on each side of the rachis ± regularly arranged, ± alternate below, subopposite above, dark green above, densely white flocculent-indumentose below, rhomboid, to 20 cm long by up to 8 cm wide at widest point, the uppermost leaflets generally much shorter, the lowermost leaflets sometimes much narrower but usually almost as long as the largest leaflets; upper 2 margins praemorse, all leaf margins bearing minute bristles; main veins 15-20 radiating from the leaflet base, transverse veinlets moderately prominent above, obscured by indumentum beneath; emerging leaf pink, rapidly turning dull brown then green. Staminate and pistillate inflorescences superficially similar, pen- dulous on a peduncle 6-15 cm long, 2-3 mm diam., armed with radiating spines 2-10 mm long, peduncle adnate to the leaf sheath above the sub- tending leaf. Prophyll pale pinky-green at first, later green, then drying to cinnamon-brown at anthesis, with scattered whitish indumentum and brown scales, 11-24 x 1.5-3.0 cm, the beak portion ± 1.5-2.5 cm long, rarely longer, unarmed except for a few reflexed spines on the margins at the very base; apical splits 1 x 1.5 mm. Axis with 4 to 6 first-order branches; first-order bracts tightly sheathing for c. 0.5 mm, long-apiculate to 4 mm. Staminate flowers solitary, creamy-yellow at anthesis, borne on an alveolus c. 0.5 mm diam., whole flower c. 5 mm long; calyx c. 1 mm high, very shallowly lobed; corolla c. 4-5 mm long, lobed ? to the base, petals c. 2 mm wide with triangular tips; stamens 6; filaments 0-7 mm high; anthers c. 2 x 0-8 mm; pistillode minute; pollen bright yellow. Pistillate flower similar to staminate, borne on an alveolus c. 1 mm diam., each with a sterile staminate flower; pistillate flower c. 5 mm long; calyx c. 1.5 mm high, with 3 lobes c. 0-5 mm high; corolla c. 4-5 x 2 mm, split in 3 petals for about 3/4 of total length; staminodal ring epipetalous, minute, with 6 tiny lobes c. 0.3 mm long; ovary c. 1.5 mm diam., rounded, tipped by 3 divergent, rugose, sinuous, fleshy stigmas c. 2 mm long. Sterile staminate flower c. 5 mm long; calyx c. 1 mm high, very shallowly lobed; corolla c. 4.5 mm, lobed ± to the base, the petals 1.5 mm wide; staminodes c. 1.5 mm long by 0.3 mm wide. Mature fruit narrowly ellipsoidal tipped with the stigmatic remains, c. 12 mm long by 5 mm diam. at the widest point, covered by 12-13 vertical rows of shiny chestnut-brown, pale-edged, reflexed scales with dark sub- marginal lines, to 2 x 1.5 mm. Seed covered with a thin sweetish sarcotesta to 0.75 mm thick; diaspore ellipsoidal, slightly pointed apically, somewhat flattened on one side, with a shallow lateral groove; endosperm homo- geneous; embryo basal. Germination adjacent-ligular; eophyll with 4-6 very faintly praemorse leaflets held in a broad horizontal fan. (Dransfield, J. 1979: A monograph of Ceratolobus (Palmae))A

Materials Examined

  • JAVA. West Java: Gunung Cibodas, Ciampea: R. C. Bakhuizen v.d. Brink 7222 (BO); Backer 25,438 (BO, L); 11 June 1896, Hallier s.n. (BO, L); van Steenis 2676 (BO). Pelabuan Ratu, Dec. 1927, Beaumde s.n. (L); Dransfield 1103 (BO, K, L), 1104 (BO, K, L), 1513 (seed cult. in Hort. Bogor.), 2519 (seed cult. in Hort. Bogor.), 2520 (BO), 2766 (BO), 2767 (BO), 3509 (seed cult. in Hort. Bogor.) & 3910 (seed cult. in Hort. Bogor.); Koorders 34576 p (BO); Junghuhn s.n. (L); 1888, Boerlage s.n. (FI). Cikepuh, South Coast; Frank 123 (BO). Depok: Beaumde 6760 (BO); Koorders 43130 p (BO), 44105 8 (BO, K, L). Sindanglaya, Ploem s.n. (BO). Java without precise locality, Blume s.n. (lectotype L; isolectotypes BR, FI, L), Reinwardt 1043 (K, L). CULTIVATED. In Hort. Bogor.: Beccari s.n. (FI); Koorders 42803 p (BO, L); Furtado SFN 30814 (BH, K, L, SING). (Dransfield, J. 1979: A monograph of Ceratolobus (Palmae))A

Bibliography

    A. Dransfield, J. 1979: A monograph of Ceratolobus (Palmae)
    B. World Checklist of Arecaceae