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Nomenclature etc. JUGLANDACEAE. Important species : Pterocarya fraxinifolia (Lam.) Spach (Asia minor), P. hupehensis Skan (China), P. macroptera Batalin (China), P. rhoifolia Sieb. & Zucc. (China, Japan), P.stenoptera C. de Candolle (China, Korea, Taiwan), P. tonkinensis (Franch.) Dode (S-China, Laos, Vietnam). Trade and local names: feng yang (CN); sawagurumi (JP); Chinese, Japanese wingnut (GB, US), sohm (LA).
Description based on 4 specimens. Tree. Geographic distribution: temperate Asia, Thailand, Laos, Vietnam, Cambodia.
General. Growth ring boundaries distinct. Heartwood basically brown, white or grey. Sapwood colour similar to heartwood colour. Density 0.4 g/cm³.
Vessels. Vessels present. Wood semi ring porous or diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Average tangential vessel diameter 100–120–150(–190) µm. Average number of vessels/mm² (3–)5–8. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–11(–12) µm, average diameter (vertical) large. Vessel-ray pits with reduced borders or apparently simple, similar to intervessel pits, rounded or angular, of uniform size or type, located throughout the ray. Helical thickenings absent. Tyloses present, thinwalled.
Tracheids and fibres. Fibres very thin-walled, or of medium wall thickness. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma present, banded. Bands marginal (or seemingly marginal). Bands fine. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per strand: (3–)6–8.
Rays. Rays 7–10 per tangential mm, multiseriate, 1–2(–3) cells wide. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular), or two or more cell types (heterocellular); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells.
Storied structures. Storied structure absent.
Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes absent.
Mineral inclusions. Crystals not observed. Silica not observed.
Physical and chemical tests. Froth test negative.
Illustrations. • Transverse section. Pterocarya fraxinifolia. • Axialparenchym. Pterocarya fraxinifolia. typical distribution pattern of axial parenchyma (diffuse-in-aggregates). • Tangential section. Pterocarya fraxinifolia. • Radial section. Pterocarya fraxinifolia.
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’.
