80 A HANDBOOK OF CONIFER.E 



a large scale with two ovules at the base. Mature cones erect 

 on the upper branchlets, with closely overlapping, fan-shaped 

 scales and hidden or protruding bracts ; scales and bracts falling 

 as soon as the seeds are ripe and leaving the persistent axis on 

 the tree. Seeds winged, ripening during the first autumn. Cotyle- 

 dons usually 5-7, with stomata on the upper surface. 



The genus Abies is easily distinguished from all other conifers 

 by the disc-like leaf scars and by the erect cones which break up 

 as soon as the seeds are ripe. 



The wood is odourless and varies in colour from white to 

 yellowish or reddish brown according to species, no very distinct 

 line separating sap wood and heartwood. Resin ducts normally 

 absent, but sometimes occurring after an injury ; medullary rays 

 very fine. Wood soft, easily worked, finishing with a good surface, 

 taking paint and polish well, and suitable for the indoor finish 

 of houses, the commoner kinds of joinery, pit props, scaffold poles, 

 matchwood, wood wool, paper pulp, and box boards. Owing to 

 its inodorous character it is in demand for butter, lard, and 

 grocery boxes. After treatment with a preservative it is some- 

 times used for telephone poles and for piles. 



From resin blisters on the bark oleo-resin is obtained. It is 

 known commercially as Canada balsam and Strasburg turpen- 

 tine, and is used for varnishes, mounting microscopic specimens, 

 and for medicinal purposes. An essential oil obtained from the 

 leaves is sometimes used in pharmacy. 



The silver firs require moist soil and give the best results in 

 a damp climate. They are injured by an impure atmosphere 

 and are unsuitable for the vicinity of manufacturing towns, but 

 thrive in the moist glens and valleys of W. England and Scotland. 

 They withstand a good deal of shade, and some species are useful 

 for underplanting thin woods. Although less suitable for exposed 

 positions than some of the pines, they may be grown at the limit 

 of tree growth in Britain if shelter is provided. 



The rarer silver firs are sometimes increased by grafting upon 

 commoner species, but this method of propagation is not recom- 

 mended, as grafted plants rarely grow into good specimens. 

 Whenever possible plants should be raised from seeds. These 

 may be sown in early spring ; those of rare species in pots or boxes 

 indoors and those of the commoner kinds in nursery beds in light, 

 well-worked soil. Seedlings will usually stand for two summers 

 in nursery beds when they should be transplanted into nursery 

 lines. For forest planting trees should not exceed 15 in. in height, 

 but for decorative work specimens up to 5 ft. high may be moved 

 successfully, provided they have been transplanted biennially 

 whilst in the nursery. They bear moving better than pines and 

 may be transplanted during open weather between early October 

 and late March, or in late districts until the end of May. 



