Identification key

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Coniferous wood		Wood without vessels (pores), with tracheids only
Pitting in rays	Resin canals	Transversal tracheids	Spiral thickenings in tracheid walls	Species	Key characteristics
large (pinoid pits)	present	present	absent	Pinus sylvestris	Transversal tracheids with dentated walls, cannot be differentiated from P. mugo and P. nigra.
				Pinus mugo	Transversal tracheids with dentated walls, cannot be differentiated from P. sylvestris and P. nigra.
				Pinus nigra	Transversal tracheids with dentated walls, cannot be differentiated from P. sylvestris and P. mugo, sometimes early-/latewood transition seems more abrupt than in the two other species.
				Pinus cembra	Transversal tracheids with smooth walls, in general small growth rings, latewood zones always narrow.
				Pinus strobus	Transversal tracheids with smooth walls, in general larger growth rings, latewood zones narrow, similar to P. cembra.
small	present	present	absent	Picea abies	Transition from early- to latewood continuous. Resin canals with thick-walled epithelial cells. Bordered pits in axial tracheids generally uniseriate.
				Larix decidua	Transition from early- to latewood abrupt. Resin canals with thick-walled epithelial cells. Bordered pits in axial tracheids often biseriate.
			present	Pseudotsuga taxifolia	Transition from early- to latewood abrupt. Resin canals with thick-walled epithelial cells. Fine spiral thickenings.
	absent	absent	absent	Abies alba	Transition from early- to latewood abrupt. In radial section the tangential ray cell walls show distinct nodular chains.
				Juniperus communis	Colored deposits in parenchyma cells, smooth walled ray cells.
			present	Taxus baccata	Distinct spiral thickenings.


Dicotyledon wood		Wood with vessels (pores)

Ring-porous wood
Ray width	Perforation plates	Spiral thickenings	Species	Key characteristics
uniseriate	simple	absent	Castanea	Latewood with dendritic pore arrangement, rarely biseriate rays.
bi- to triseriate	simple	absent	Fraxinus	Latewood pores solitary or in small radial groups, thickwalled.
bi- to triseriate	simple	present	Hippophaë	Ring-porous, sometimes semi-ring-porous, rays generally storied.
3- to 5-seriate	simple	present	Ulmus	Pores, vascular tracheids and parenchyma in latewood in tangential to slightly oblique bands.
3- to 5-seriate	simple	present	Robinia	Pores, vascular tracheids and parenchyma in latewood in clusters to short bands, conspicuous tyloses.
>5-seriate	simple	absent	Vitis	In the narrow latewood pores in radial files and small groups. Rays very wide. Vessels with scalariform pits.
		present	Clematis	Latewood generally narrow, growth ring boundaries festoonlike, large rays.
			Berberis	Ring-porous to semi-ring-porous, latewood pores and vascular tracheids in clusters with a tangential to diagonal or dentritic orientation.
			Laburnum	Growth ring boundaries festoonlike, rays often over 5 cells wide, gum deposits in the heartwood vessels.
			Ailanthus	Often slightly oblique to tangential parenchyma bands, often indistinct ring-porous, variable.
uni- and multiseriate	simple	absent	Quercus	Dendritic pore groups in the latewood, uniseriate and very broad rays.
uni- and multiseriate	simple	present	Rosa	Broad rays often over 10 mm high.


Diffuse- and semi-ring-porous wood
(uniform distribution of pores)
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
uniseriate	homo- geneous	simple	absent	Populus	Large and simple ray-vessel pits.
			present	Aesculus	Pores solitary or in radial rows of two to some pores.
			present	Euonymus	Numerous small pores.
		scalariform	absent	Alnus viridis	Pores in radial multiples, rarely in clusters, scattered.
				Alnus glutinosa Alnus incana Corylus	See aggregate rays.
				Betula nana Betula humilis	Extremely small numerous ray-vessel pits, occasionally bi- to 4-seriate rays.
	hetero- geneous	simple	absent	Salix	Large and simple ray-vessel pits.
	hetero- geneous	simple	present	Daphne	Pores loosely packed in dendritic patterns.
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
bi- to tri- seriate	homo- geneous	simple	absent	Juglans	Pores large, infrequent, solitary or in radial rows of 2 to 4 cells.
			absent to (sometimes: occasionally) present	Maloideae: Amelanchier, Cotoneaster, Crataegus, Cydonia, Mespilus, Pirus, Sorbus	Numerous to very numerous small pores, often indistinctly semi-ring-porous, occasionally with fine spiral thickenings.
			present	Hippophaë	Generally semi-ring-porous, sometimes ring-porous, rays generally storied.
				Acer	Pores widely spaced, solitary or in radial files of 2 to 3 pores.
				Prunus	See 3- to 5-seriate rays, slightly heterogeneous.
				Tilia	Vessel outlines angular, radially orientated pore files and clusters. Rays flare along growth ring boundaries.
		scalariform	absent	Betula	Extremely small numerous ray-vessel pits, scattered pores in radial files of 2 to 4, or clusters.
	hetero- geneous	simple	present	Frangula	Generally semi-ring-porous, pores rather widely spaced, especially in latewood.
				Lonicera	Multiseriate rays conspicuously heterogeneous with numerous rows of square and upright marginal cells.
				Ligustrum	Rays often with 1-2 (4) rows of square and upright marginal cells.
				Ostrya	Pores infrequently, in radial multiples of 2 to 10 pores.
				Prunus	See 3- to 5-seriate rays, slightly heterogeneous.
				Sambucus	See 3- to 5-seriate rays.
		scalariform	absent	Buxus	Narrow pores, round to oval scalariform perforation plates with mostly <10 bars.
				Viburnum	Rays conspicuously heterogeneous, perforation plates scalariform with >20 bars.
				Cornus	Rays markedly heterogeneous, more likely 3- to 5-seriate, scalariform perforation plates with many bars.
			present	Viburnum	Rays conspicuously heterogeneous, perforation plates scalariform with >20 bars. Fine spiral thickenings in the fibre tracheids: Viburnum lantana.
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
3- to 5- seriate	homo- geneous	simple	absent	Juglans	Pores large, infrequent, solitary or in radial rows of 2-4 cells.
			present	Prunus	Diffuse-porous to semi-ring-porous, pores solitary or in radial rows of two to some cells or in clusters, gum deposits in heartwood vessels. Rays in some species frequent >5-seriate.
				Acer	Pores widely spaced, solitary or in radial files of 2 to 3 pores.
				Tilia	Vessel outlines angular, radially orientated pore files and clusters. Rays flare along growth ring boundaries.
		scalariform	absent	Betula	Extremely small numerous ray-vessel pits, scattered pores in radial files of 2 to 4, or clusters.
	hetero- geneous	simple	absent	Sambucus	Pores in clusters, mostly marginal bands of thin-walled vascular tracheids. Rays with sheath cells.
		simple	present	Prunus	Diffuse-porous to semi-ring-porous (P. armeniaca to ring-porous), pores solitary or in radial rows of two to some cells or in clusters, gum deposits in heartwood vessels. Rays in some species frequent >5-seriate.
		scalariform	absent	Cornus	Rays markedly heterogeneous, 3- to 5-seriate, scalariform perforation plates with many bars.
		scalariform	present	Ilex	Pores small, in long radial files, rays often up to 4mm high.
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
> 5-seriate often or predomi- nantly	homo- geneous	simple	absent	Fagus	Diffuse- to semi-ring-porous, rays very large, perforation plates both simple and scalariform.
				Platanus	Similar to Fagus, more often large rays, pits in vessel walls in horizontal rows.
				Hedera	Pores in clusters, predominantly tangentially orientated.
			present	Clematis	Very large pores, see ring-porous wood.
			present	Berberis	See ring-porous wood.
		scalariform	absent	Fagus	Diffuse- to semi-ring-porous, rays very large, perforation plates both simple and scalariform.
		scalariform	absent	Platanus	Similar to Fagus, more often large rays, vessel pits opposite, in horizontal rows.
	hetero- geneous	simple	absent	Hedera	Pores in clusters, predominantly tangentially orientated.
		simple	absent	Vitis	See ring-porous wood.
		scalariform	present	Ilex	Pores small, in long radial files, rays often up to 4mm high.
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
uniseriate and/to multiseriate	homo- geneous to hetero- geneous	simple	absent	Fagus	Diffuse- to semi-ring-porous, rays very large, perforation plates both simple and scalariform.
				Clematis Quercus Fraxinus	Ring-porous wood with very narrow rings appears sometimes similar to diffuse-porous wood, see ring-porous wood.
				Clematis Quercus Fraxinus
			present	Rosa	Ring-porous wood with very narrow rings appears sometimes similar to diffuse-porous wood, see ring-porous wood.
			present	Prunus	Diffuse-porous to semi-ring-porous (P. armeniaca to ring-porous), pores solitary or in radial rows of two to some cells or in clusters, gum deposits in heartwood vessels.
		scalariform	absent	Ribes	Rays often with sheath cells.
		scalariform	present	Fagus	Diffuse- to semi-ring-porous, rays very large, perforation plates both simple and scalariform.


Diffuse- and semi-ring-porous wood with aggregate rays
(uniform distribution of pores)
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
uniseriate and irregularly multiseriate	homo- geneous to hetero- geneous	simple	present	Carpinus	Pores in long radial files.
		scalariform	absent	Alnus glutinosa	Pores in radial multiples, perforation plates with generally more than 10 bars.
				Alnus incana	Cannot be differentiated from A. glutinosa.
				Corylus	Pores in radial multiples, often in dendritic arrangement, perforation plates with 5 to 10 bars.
			present	Corylus	Fine spiral thickenings are frequent.


Diffuse- and semi-ring-porous wood, dendritic groups of pores
Ray width	Ray type	Perforation plates	Spiral thickenings	Species	Key characteristics
2- to 3- seriate	homo- geneous to hetero- geneous	simple	present	Rhamnus	Dendritic pore distribution.
2- to 3- seriate	homo- geneous to hetero- geneous	simple	present	Daphne	Pores loosely packed in a dendritic pattern.


Diffuse- and semi-ring-porous wood, pores hardly differentiable from axial and ray parenchyma
				Species	Key characteristics
				Viscum album	Vessels, parenchyma and growth ring boundaries indistinct.

/ authors / citation / 11.05.05

Identification key

Coniferous wood

Wood without vessels (pores), with tracheids only

Dicotyledon wood

Wood with vessels (pores)

Ring-porous wood

Diffuse- and semi-ring-porous wood

Diffuse- and semi-ring-porous wood with aggregate rays

Diffuse- and semi-ring-porous wood, dendritic groups of pores

Diffuse- and semi-ring-porous wood, pores hardly differentiable from axial and ray parenchyma