KEY TO THE CONIFEROUS WOODS INCLUDED IX THE COURSE 



1. Wood with a sweet aroma (at least when worked) . Pencil Cedar 



1 a. Woods which are either scentless or have a balsamic or resinous 



odour 2 



2. A scentless wood of a rich red colour, very soft and light, resin-cells 



present but rare Giant Redwood 



2 a. Woods either scentless or having a balsamic odour but in any case 



having no resin-cells 3 



3. Xo resin-canals either vertical or horizontal 4 



3 a. Resin-canals of both kinds present (make sure of the horizontal 



canals) 5 



4 . Wood very heavy and hard : colour dark brown, very little difference 



between the Spring and Autumn wood . . . Yew-tree 



4 a. Wood very light in colour and in weight: colour whitish or 



yellowish Silver Fir 



5. Wood light in weight and colour 6 



5 a. Wood medium to heavy: colour (of the Autumn wood at least), 



dark brown or reddish 7 



6. One large pit, or at most two, pits in the cross-field ... 9 



6 a. Two or more small pits in the cross-field: vertical resin-canals rare 



and casual Spruce 



7*. One (or but rarely two) large pits in the cross-field: balsamic smell 

 (worked). Reaction with perchloride of iron slight or none . 



Scots Pine (heart) 



7 a. More than one large pit in the cross-field (mostly two, but even 



three or four) 10 



7 b. More than one small pit in the cross-field (never one large one 



only: no smell when worked (dry)). Reaction with per- 

 chloride of iron, inky 8 



8. Rays in tangential section, stout; the horizontal resin -canal 



within them does not occupy the whole width of the middle: 

 spiral tracheids present Douglas Fir 



8 a. Rays in tangential section, long drawn-out, slender: the canal 



within them occupies the whole width of the middle : tracheids 

 not spirally thickened as a rule Larch 



9. Wood very soft and light, feebly resinous; smell when worked, 



feeble: generally two large pits in the Spring cross-fields and 

 one in the Autumn Pinus Strobus 



9 a. Wood moderately hard: smell when worked, powerfully resinous: 



one large pit in all cross-fields, very rarely two 



P. sylvestris (sapwood) 

 10. Wood light in weight and colour: one or two large pits in the 



cross-field P. Strobus 



10 a. Wood heavy and highly charged with resin: often four large pits 



in the cross-field P. palustris 



* Note that there are more than two alternatives here. 



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