862, ARBORETUM ET FRUTICETUM BRITANNICUM. 
diges’s collection (the most complete in Europe, unless we except that of M. 
Vilmorin,) are propagated by grafting on the common oak, close to the 
ground ; and largely earthing up the grafts afterwards, so as to leave only the 
points of the scions exposed to the air. This earthing up not only preserves 
a uniform degree of moisture round the graft ; but the earth employed being 
taken from the adjoining surface, and consequently having been heated by the 
sun, produces an immediate increase of temperature round the graft, which 
gives an impulse to the rising sap, and so accelerates vegetation. We had the 
advantage, in August, 1840, of examining all the American oaks in the Bois 
de Boulogne, in company with M. Michaux, who sowed the acorns in 1822 ; 
and we there observed, as we had previously done in the Hackney Arboretum, 
that much the most rapid, vigorous, and erect growing species was Q. pa- 
lastris ; next Q. coccinea, which resembles Q. palistris, but with leaves on a 
larger scale; then Q. rubra; and, next to that species, Q. nigra and Q. tinc- 
toria. Q. alba is not in the Bois de Boulogne, the acorns, as M. Michaux 
informed us, rarely retaining their vitality during the time requisite 20 years 
ago to bring them to Europe. 
§ ili. A’lbe. White American Oaks. 
Sect. Char. eaves lobed, and sinuated, not mucronated; broadest at the 
upper extremity ; dying off more or less shaded witha violet colour. Bark 
white, or whitish brown, cracking and scaling off in thin lamine. Fructifi- 
cation annual. Cups imbricate or echinate. Nut oblong, generally large. 
¥ 8. Q. a’uBA Lin. The American white Oak. 
Identification. Lin. Sp. Pl., 1414. ; Pursh, vol. 2. p. 633.; Michx. Quer., No. 4. t. 5. 
Synonymes. Q. Alba virginiana Park. Theat. Bot.; Q.a. pinnatifida Walt. Carol. p. 230. No. 10.; 
Q. paldstris Marsh. p. 120. No. 3.; Chéne blanc de l’Amérique, Fy. ; weisse Eiche, Ger. 
Engravings. Cat. Carol., 1. t. 21. f. 2.; Michx. N. Amer. Syl., vol. 1. t.1.; the plate of this tree in 
Arb. Brit., Ist edit., vol. vii. ; and our jig. 1569. 
Spec. Char., §c. Leaves oblong, pinnatifidly serrated; pubescent underneath : 
lobes linear-lanceolate, obtuse, entire, attenuated at the base. Fruit pedun- 
culated. Calyx somewhat cup-shaped, warty, and flattened at the base. 
Acorn oval. (Willd.) A large deciduous tree. North America, Height 
60 ft. or upwards. Introduced in 1724. Flowers greenish white; April. 
Varieties, The elder Michaux gives the two following forms of this species, 
the leaves of both of which are shown in fig. 1567. copied from Michaux’s 
Histoire des Chénes Amériques : — 
¥ Q. a. 1 pinnatifida Michx. (Hist. des 
Chénes Amér., t. 5. f. 1.; and our fig. 
1567. a.) Q. Alba Ban. Cat. Stirp. 
Virg.; Q. virginidna Catesb. Carol. i. 
p. 21. t. 21.; Q. a. palistris Marsh. 
p- 120. No. 3.— The usual form of 
the species, and com- 
NN mon from Canada to 
Y Florida. Fig. 1568. 
is a sprig and acorn 
S of Q. alba pinnati- 2 
fida, taken from Mi- 
chaux’s North Ameri- 
can Sylva, vol.i. t. 1. 
and theacorn without 
its calyx is shown in | 
1567. Q.a.pinnatifida. fig, 1566, at a. 1568. @. a. pinnatifida. 
£ Q. a. 2 repdnda Michx. (Hist. des Chénes, t. 5. f. 2.; and our jig. 
1567. 6. — Found wild in the forests of Carolina, and sometimes oc- 
curring in seed-beds of Q. alba in Europe. Fig. 1569. is from a sprig 
