Naturalisation in Extra-Tropical Countries. 451 



Quercus Prinus, Linne. 



The Swamp-Oak or Rock-Chestnut-Oak. South-Eastern States 

 of North- America. A tree, becoming 90 feet high ; aged stem as 

 much as 15 feet in girth [Meehan]. Likes rocky hill-sides [Fer- 

 now]. The tree is hardy in Norway to lat. 59 55'. Foliage 

 deciduous. Wood strong and elastic, but more porous and of a 

 coarser grain than that of the white oak ; according to Porcher it 

 is easy to split and not hard, used for building purposes, also cooper- 

 age. A red dye is produced from the bark ; the latter is one of the 

 most important among oak-barks for tanning, as it furnishes a very 

 solid and durable leather. 



Quercus reticulata, Humboldt. 



Cooler regions of Mexico and Arizona. The wood approaches in 

 quality that of the white oak [Pringle]. 



Quercus Bobur, Linne.* 



The British Oak. Extending through the greatest part of Europe, 

 also to Western Asia, attaining a great age and an enormous size. It 

 endures the frosts of Norway as far north as 65 54' ; while in lat. 

 59 40' a tree measured was 125 feet high and 25 feet in circum- 

 ference of stem [Schuebeler]. Over 700 sound annual rings have 

 been counted, and it has even been contended, that oaks have lived 

 through 1,500 years. At Ditton-Park, owned by the Duke of 

 Buccleugh, is an ancient oak, assumed to be 600 years old, with 

 a stem-circumference of 30 feet at some distance (a few feet) from 

 the ground [Dr. Masters and Th. Moore]. An oak at Lichfield 

 measures at the base of its stem 80 feet in girth [Dr. M. T. Masters]. 

 The stem of the Panshanger-oak in 1873 measured 73 feet in circum- 

 ference at 2 feet from the ground ; at 22 feet it was 16^ feet in 

 girth [R. B. Smith]. Two trees of the variety pedunculata, in 

 Hesse, have a stem, which 3 feet above the ground measures 37^ 

 feet in circumference. The much and long admired Giant-Oak at 

 the Unstrut (Germany), when felled at the age of 600 years, had the 

 wood perfectly sound everywhere. The stem was 6 feet in diameter. 

 Oaks have been known to gain a stem 12 feet in diameter at the base, 

 10 feet in the middle and 5 feet at the main-branches At St. 

 Vincent's Gulf the British Oak grew in 40 years to 66 feet in height 

 [R. B. Smith]. Two varieties are distinguished : 1. Q. sessiliflora 

 (Salisbury), the Durmast-Oak, with a darker heavier timber, more 

 elastic, less fissile, easier to bend under steam. The woodwork of 

 Westminster Abbey is of this variety [Masters]. This tree is also 

 the quicker of the two in growth, and lives in poorer soil. Its bark 

 is richer in medicinal, dyeing and tanning principles. 2. Q. pedun- 

 culata (Ehrhart). This variety supplies most of the oak-timber in 

 Britain for ship-building, and is the best for many kinds of cabinet- 

 makers' and joiners' work ; most important also for staves. Saplings 

 and branches in demand for walking sticks. In Britain the oak 



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