LARCH G.Nl 8311 



LARCH 



Larix europcea, DC. Coniferae. Abietinese. 



A moderately hard and heavy wood of a brownish-white, striped very 

 broadly with darker resinous-brown bands. In the lighter coloured wood 

 it resembles Scots Fir, in the darker, Douglas Fir, and in such cases it 

 is impossible to distinguish it except by the structure. Smell, none when 

 worked, at least when the wood is quite dry (compare Scots Fir, which 

 has a powerful resinous smell when worked). The smell is revived by 

 warming. Reaction with perchloride of iron, inky. 



Structure, much as Pinus sylvestris. Must be observed by the micro- 

 scope. Resin-canals abundant: epithelium thick- walled. 



Spiral thickenings to the vertical tracheids either absent or weak. 



Rays with their horizontal resin-canals, slender, attenuated, acicular, 

 spindle-shaped in tangential section as in P. sylvestris (compare Douglas 

 Fir in which they are stout and boat-shaped), see Figs. 7-9. In the Larch 

 the horizontal canal occupies the whole width of the ray (compare 

 Douglas Fir in which it does not). 



Pits in the cross-field, two or more small ones of a somewhat slit 

 shape occupying but little of the space. 



Walls of the ray-tracheids, smooth. 



Pith minute, obscure. 



i 



May be confused with: May be distinguished by: 



Scots Fir when dark-coloured Many small pits in the cross- 



(pits in the cross-field, one large field, 

 one, rarely two). 



Douglas Fir (spiral thickenings Spiral thickenings rare: rays 



in the vertical tracheids : rays broad narrow and rat-tailed, 

 and short). 



41 3-6 



