I860

ARBORETUM AND FRUTICETUM.

FART III.

abundant; and sometimes not above a handful ofacorns can be found in a large forest. The acornshave a very thin and brittle shell: they ripenearly, and, according to Cobbett, germinate soeasily, that, “ if warm rains come on in the monthof November, which they very frequently do inAmerica, the acorns still clinging to the treesactually begin to sprout before they are shakendown by the winds.” (Woodlands, § 542.) Sometrees produce acorns of a deep blue colour; butMichaux had seen only two specimens of thisvariety; one in the grounds of Mr. Hamilton,near Philadelphia, and the other in Virginia. Thebark of this tree is white (whence the species de-rives its name); and, though it is often variegatedwith large black spots, it has such a silvery hue,that the tree may be easily distinguished by iteven in winter. The bark is scaly; and, on young

trees, it appears divided into squares, but, on old trees, into plates laterallyattached. The wood is reddish, somewhat resembling that of the British oak,but lighter, and less compact. The rate of growth of this tree, in British gar-dens, where the soil is good and the situation sheltered, may be considered asnearly equal to that of the common oak; but without shelter, even in a goodsoil, the tree has a stunted appearance for many years, as is evident from atree of 20 years’ growth in the Hackney arboretum, and several in the Horticul-tural Society’s Garden, of two of which Jig. 1727. presents portraits. The largest

1726

7 ,

trees that we know of are between 60 ft. and 70 ft. high; 'and, both at YorkHouse near Twickenham, and at Muswell Hill, they have ripened acorns.

Geography. Q. alba is found as far north as Canada, N. L. 46° 30'; andthence it was traced by the two Michaux, as far as Cape Canaveral, N. I.. 28°;and westward, from the ocean to the country of Illinois; a distance of above1200 miles from north to south, and nearly as much from east to west. Itis not, however, equally distributed over this extensive tract of country, beingfound either in very dry and sandy, or in very rich, soils. The white oak isin the greatest abundance in those parts of Pennsylvania and Virginia that lie