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| Commercial timbers |
Nomenclature etc. ULMACEAE. The description also applies to the second species of the genus, Phyllostylon rhamnoides, with a wide distribution from the Caribbean to northern Argentina. Trade and local names: San Domingo boxwood, West Indian boxwood (GB, US); bois blanc (DO); bois blanc (HT); jatia (CU); seron, cerón (MX); membrillo (VE); gurigica, pao branco (BR); palo lanza, p. blanco, p. amarillo, ibirá-catá, tala grande (PY, AR). Not protected under CITES regulations.
Tree. Geographic distribution: Caribbean, tropical South America (central and eastern Brazil).
General. Growth ring boundaries distinct (distinct in some specimens by larger and more frequent vessels (earlywood), by thickened (noded) rays, and by darker fibrous zones (latewood)) or indistinct or absent. Heartwood basically yellow, white or grey. Sapwood colour similar to heartwood colour. Density 0.82–0.92 g/cm³.
Vessels. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Average tangential vessel diameter 20–45–65 µm. Average number of vessels/mm² 80–120. Average vessel element length 100–170–240 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–10 µm. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular. Tyloses rarely present or absent, thinwalled. Other deposits present, vessels frequently filled with amorphous mineral contents (calcium carbonate).
Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Average fibre length 300–820–1300 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma not banded. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma scanty, vasicentric, aliform, and confluent. Aliform parenchyma of the winged type. Axial parenchyma as strands. Average number of cells per strand: 2(–4).
Rays. Rays 6–13 per tangential mm, multiseriate, (1–)2–3(–4) cells wide. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. Marginal rows occasionally formed by large procumbent cells.
Storied structures. Storied structure present, all rays storied or some rays storied, some not, axial parenchyma storied, vessel elements storied. Arrangement of tiers regular, or irregular. Number of ray tiers per axial millimetre 4–6. Storied structure often inconspicuous.
Mineral inclusions. Crystals present, prismatic and in other forms (calcium carbonate in vessels carbonate de calcium dans les vaisseaux), located in ray cells and axial parenchyma cells. Crystal-containing ray cells procumbent. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber one. Crystals in rays restricted to zones intersecting with growth ring boundaries. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract fluorescent (weak, light yellow). Colour of ethanol extract yellow. Chrome azurol-S test negative. Splinter burns to partial ash. Ash white to grey.
Illustrations. • Transverse section. characteristic calcium carbonate deposits in vessels. • Transverse section enlarged. • Tangential section. • Radial section. calcium carbonate deposits in vessels.
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: 9th April 2019. delta-intkey.com’.
