Commercial timbers

H. G. Richter and M. J. Dallwitz


Trochodendron aralioides ()

Nomenclature etc. TROCHODENDRACEAE. Status of protection under CITES regulations: not protected.

Description based on: 2 specimens. Tree. Geographic distribution: temperate Asia.

General. Growth ring boundaries distinct, rays typically widening at growth ring limits. Heartwood basically brown, without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent.

Vessels. Vessels absent.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres very thin-walled. Fibre pits common in both radial and tangential walls, distinctly bordered. Helical thickenings absent. Fibres non-septate. Tracheids with scalariform pitting; tracheids alternating with fibres.

Axial parenchyma. Axial parenchyma absent or extremely rare.

Rays. Rays present, 4–7 per tangential mm, multiseriate, also if only few, 1–8 cells wide, commonly 5–10 cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of two distinct sizes. Height of large rays commonly over 1000 µm. 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 and 2–4. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent. Uniseriate rays composed solely of square and upright cells.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes absent.

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


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