Commercial timbers

H. G. Richter and M. J. Dallwitz


Alchornea triplinervia (Spreng.)Muell. Arg.(tapi'a guasu)

Nomenclature etc. EUPHORBIACEAE. Trade and local names: tapi'a guasu, chipa rupa (PY); tapiá, caixeta, tapia-guaçu, tapiá-mirim, folha-de-bolo, tamanqueira, canela-samambaia, malacaxeta, taneiro, canela-raposa, boleiro, chico-rupa (BR). Status of protection under CITES regulations: not protected.

Description based on: 3 specimens. Tree. Geographic distribution: southern Brazil.

General. Growth ring boundaries indistinct or absent. Heartwood basically brown (according to Mainieri & Péres Chimelo (1989) colour can also be light to pinkish beige), without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent. Basic specific gravity 0.44 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows and radial rows of 4 or more. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter 120–200(–250) µm. Average tangential diameter of vessel lumina large. Average number of vessels/mm² 2–10(–20). Vessels per square millimetre few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 13–17 µm, large. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular and horizontal to vertical, of two distinct sizes or types in the same ray cell, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels present, thinwalled. Other deposits in heartwood vessels present, amber coloured organic contents.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–7(–8). Unlignified parenchyma absent.

Rays. Rays present, 14–18(–22) per tangential mm, exclusively uniseriate. Aggregate rays absent. Rays of one size. Height of large rays commonly over 1000 µm (according to Mainieri & Péres Chimelo (1989) rays can be up to 4 mm high). 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 2–4 and more than 4. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent. Biseriate rays only occasionally pesent.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes present. This refers to so-called latex traces as desribed in IAWA (1989); these are large, dark coloured openings in some rays, albeit very infrequent.

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

Mineral inclusions. Crystals present, prismatic and druses, located in ray cells. Crystal-containing ray cells upright and/or square, upright and/or square ray cells not chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. The occurrence of two crystals of the same of different size in one cell is rather rare. Silica not observed.


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