Ceratolobus glaucescens

Ceratolobus (sehr-ah-toh-LOH-buhs) glaucescens (glaw-SEHS-sens)
Bogor Botanic Garden, Indonesia. Prophyll Enclosing Inflorescence at Maturity. Photo by Dr. William J. Baker, Royal Botanic Gardens, Kew/Palmweb.
Scientific Classification
Genus: Ceratolobus (sehr-ah-toh-LOH-buhs) Species: glaucescens (glaw-SEHS-sens)
Synonyms
None set.
Native Continent
Asia
Morphology
Habit: Clustering Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Java, and Thailand. 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).

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 in diam. without sheaths, 8-13 mm in 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 in 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 about 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, pendulous on a peduncle 6-15 cm long, 2-3 mm in 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 about 0.5 mm, long-apiculate to 4 mm. Staminate flowers solitary, creamy-yellow at anthesis, borne on an alveolus about 0.5 mm in diam., whole flower about 5 mm long; calyx about 1 mm high, very shallowly lobed; corolla about 4-5 mm long, lobed ? to the base, petals about 2 mm wide with triangular tips; stamens 6; filaments 0-7 mm high; anthers about 2 x 0-8 mm; pistillode minute; pollen bright yellow. Pistillate flower similar to staminate, borne on an alveolus about 1 mm in diam., each with a sterile staminate flower; pistillate flower about 5 mm long; calyx about 1.5 mm high, with 3 lobes about 0-5 mm high; corolla about 4-5 x 2 mm, split in 3 petals for about 3/4 of total length; staminodal ring epipetalous, minute, with 6 tiny lobes about 0.3 mm long; ovary about 1.5 mm in diam., rounded, tipped by 3 divergent, rugose, sinuous, fleshy stigmas about 2 mm long.

Culture

Cold Hardiness Zone: 11