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Nomenclature etc. CERCIDIPHYLLACEAE. Not protected under CITES regulations.
Description based on 2 specimens. Tree. Geographic distribution: temperate Asia.
General. Growth ring boundaries distinct (marked by radially flattened fibres). Heartwood basically brown. Sapwood colour distinct from heartwood colour. Density 0.42–0.48 g/cm³.
Vessels. Vessels present. Wood diffuse porous. Vessels in multiples, commonly in short (2–3 vessels) radial rows and in clusters. Vessel outline rounded and angular. Average tangential vessel diameter 40–60–70 µm. Average number of vessels/mm² 140–190. Perforation plates scalariform, with 20–35 bars. Intervessel pits scalariform, average diameter (vertical) 5–7 µm. Vessel-ray pits with distinct borders and with reduced borders or apparently simple, different from intervessel pits, horizontal to vertical, restricted to marginal rows. Helical thickenings present, in narrow and wide vessel elements, only in vessel element tails. Tyloses present, thinwalled.
Tracheids and fibres. Fibres very thin-walled to of medium wall thickness. Fibre pits common in both radial and tangential walls, distinctly bordered.
Axial parenchyma. Axial parenchyma present. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per strand: 6–9.
Rays. Rays 7–10 per tangential mm, multiseriate, 1–2 cells wide. Height of large rays up to 500 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells or mostly 2–4 marginal rows of upright or square cells. Sheath cells absent.
Mineral inclusions. Crystals not observed. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract weakly fluorescent; colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown. Chrome azurol-S test negative. Splinter burns to charcoal.
Illustrations. • Transverse section. • Tangential section. long and steeply inclined scalariform perforation plates (left). • Radial section. scalariform perforation plate with many bars. • Intervessel; vessel-ray pitting. ray composition, horizontal ray-vessel pitting, scalariform perforation plates, tyloses. • Helical thickenings. helical thickenings only in vessel element tails (not in all specimens observed).
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’.
