Page:TheTreesOfGreatBritainAndIreland vol02B.djvu/150

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288
The Trees of Great Britain and Ireland

pairs of rounded lobes, the lateral nerves reaching to the sinuses as well as to the lobes; coriaceous; under surface bluish green, with a stellate pubescence, often discernible only with a lens. Fruit: 2 to 6 on a long stalk, very large, the acorns being 45 inch in diameter. The cups look very distinct from those of the common oak,

This species is considered by Zabel’ to be a hybrid between Q. pedunculata and Q. lanuginosa, but it seems rather to be a geographical form of Quercus pedunculata, Elwes saw two stunted trees which may be this at Orton Hall, Peterborough, said to have been raised from acorns sent by the late Sir H. Layard from Kurdistan.

The following three species or geographical forms were considered to be varieties of Quercus pedunculata by De Candolle.

Quercus Brutia, Tenore, Sem. Ann. Hort. Neap. (1825), p. 12.—Occurs in southern Italy. The difference between it and some northern forms of Q. pedunculata is very slight, as the leaves are glabrous. The fruit is large and somewhat peculiar.

Quercus Thomasii, Tenore, loc. cit. This also occurs in southern Italy, and is a form with large acorns, having leaves pubescent on the under surface, and standing on short pubescent petioles.*

Quercus apennina, Lamarck, Encyc. i. 725 (1783).—This is a small oak which occurs on dry situations in the south of France, and is said to form considerable forests in the Apennines in Italy. It has hoary, tomentose shoots and small leaves, with the under surface pale pubescent, and shorter stalks than Quercus lanuginosa, which it otherwise much resembles. The fruit is crowded on thick grey tomentose axes, and the cupules are greyish tomentose with appressed scales.

Hybrid or Intermediate Forms.—Hybrids between Quercus sessiliflora and Q. pedunculata occur; but they seem to be rare in the wild state in England, and I have only seen two or three specimens which could not at a glance be referred to one or other species without doubt. The best name for the hybrid is Quercus intermedia, Boenn, in Rchb. Fl. Germ. 177 (1830). The type specimen of Q. intermedia, Don, obtained by Leighton in Wyre Forest, Shropshire, is true sessiliflora. Another specimen in the British Museum labelled intermedia, gathered in 1843 in Surrey, is pedunculata; in this some of the peduncles are rather short, but there is one fully developed peduncle of the usual length, and the leaves in no way differ from ordinary pedunculata. What is often supposed to be intermedia is, however, the common oak, bearing leaves with stalks of a moderate length. The word pedunculata is apparently a trap to deceive all but the practised botanist. In Q. pedunculata the acorns are sessile on a long peduncle, which is distinct from a shoot, as it bears only acorns, never buds or leaves. I have received specimens from professional foresters, labelled “sessiliflora, intermediate form," in which the


1 Laubholz-Benennung, 78 (1903).

Elwes has received seedlings of both these forms from Herr Sprenger of Naples, and has sent some of them to Kew; but they do not at present show any appreciable difference, which was the case also in the oaks which he saw growing in the Sila mountains in Calabria.