Commercial timbers

H. G. Richter and M. J. Dallwitz


Cratoxylum arborescens Bl. (Geronggang)

Nomenclature etc. GUTTIFERAE. Trade and local names: geronggang (MAL,RI); serugan (MAL-Sab). Status of protection under CITES regulations: not protected.

Tree. Geographic distribution: Thailand, Laos, Vietnam, Cambodia, or Indomalesia.

General. Growth ring boundaries indistinct or absent. Heartwood basically light brown red, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Basic specific gravity 0.42–0.55 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in diagonal and/or radial pattern, in multiples, commonly short (2–3 vessels) radial rows or radial rows of 4 or more. Two distinct vessel diameter classes absent. Average tangential vessel diameter 150–250 µm. Average number of vessels/mm² 5–8. Some of the larger vessels typically appended with many small vessels either in radial rows or as irregular clusters. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present (reddish brown).

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty, or vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 8–15.

Rays. Rays 8–11 per tangential mm, multiseriate, also if only few, 1–2(–3) cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. Rays composed of two or more cell types. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells 1.

Storied structures. Storied structure absent.

Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells. Silica particles mostly small, more or less circular and with smooth surface.


Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.

Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).

Index