Commercial Timbers


H. G. Richter and M. J. Dallwitz

Dactylocladus stenostachys Oliv. (Jongkong)

Nomenclature etc. MELASTOMATACEAE. Trade and local names: jongkong (ID, MY. Not protected under CITES regulations.

Description based on 3 specimens. Tree. Geographic distribution: Indomalesia.

General. Growth ring boundaries indistinct or absent. Heartwood basically brown, without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent. Density 0.41–0.61 g/cm³. Heartwood pinkish to red brown, often with dark flecks.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Vessel outline angular. Two distinct vessel diameter classes absent. Vessels mostly solitary. Average tangential vessel diameter 120–200–260 µm; diameter of vessel lumina: large and very large. Average number of vessels/mm² 2–6; vessels per square millimetre very few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–12 µm, medium, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits and different from intervessel pits, of two distinct sizes or types in the same ray cell, of the same type in adjacent elements, located throughout the ray. Ray-vessel pits often elongated horizontally. Helical thickenings absent. Tyloses in vessels absent. Other deposits in heartwood vessels not observed.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled and of medium wall thickness. Fibre pits common in both radial and tangential walls, distinctly bordered. Helical thickenings absent. Fibres non-septate. Fibres partly with conspicuously bordered pits.

Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma winged. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 6–8. Unlignified parenchyma absent.

Rays. Rays present, 8–12 per tangential mm, exclusively uniseriate. Aggregate rays absent. Rays of one size. Height of large rays commonly 500 to 1000 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals present, radial type. Laticifers or tanniniferous tubes present. With large radial breakdown areas within some rays (no intercellular canals!) which appear on tangential surfaces as dark, lenticular flecks or holes, often visible to the naked eye.

Cambial variants. Included phloem absent. Other cambial variants absent.

Mineral inclusions. Crystals not observed. Cystoliths absent. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.

Illustrations. • Transverse section. Dactyloclados stenostachys. • Tangential section. Dactyloclados stenostachys. • Radial section. Dactyloclados stenostachys. • Breakdown area. Dactyloclados stenostachys. Radial breakdown area as seen in tangential section.

The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.

Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 25th June 2009.’.