Commercial timbers

H. G. Richter and M. J. Dallwitz


Sideroxylon obtusifolium (Roem. & Schult.) Penn. (yvyra hu)

Nomenclature etc. SAPOTACEAE. Synon.: Bumelia obtusifolia Roem. et Schult. Trade and local names: yvyra hu, yvyra jepoka (PY); ibira-niná, guaraniná, palo de lanza, horco molle, palo piedra(RA). Status of protection under CITES regulations: not protected.

Description based on: 4 specimens. Tree. Geographic distribution: southern Brazil and temperate South America.

General. Growth ring boundaries indistinct or absent. Heartwood basically yellow, without streaks. Sapwood colour similar to heartwood colour. Basic specific gravity 0.75–0.8 g/cm³.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in diagonal and/or radial pattern and dendritic 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 30–60–75 µm. Average tangential diameter of vessel lumina medium. Average number of vessels/mm² 35–55. Vessels per square millimetre moderately numerous and numerous. Average vessel element length 364 µm. Average vessel element length medium. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–6 µm, small, not vestured. Vessel-ray pits with distinct borders and with reduced borders or apparently simple, similar to intervessel pits and 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 absent. Other deposits in heartwood vessels not observed.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres very thick-walled. Average fibre length 1000 µm. Average fibre length medium. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), bands much wider than rays, fine, up to three cells wide and coarse, more than three cells wide, 3–5 per radial mm. Axial parenchyma apotracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–6(–8). Unlignified parenchyma absent.

Rays. Rays present, 10–15 per tangential mm, multiseriate, also if only few, 2–3(–4) cells wide, 2–3 cells wide. Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays up to 500 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 distinct.

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 present, in form of crystal sand, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square. Cystoliths absent. 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