Collins Complete Guide to British Trees: A Photographic Guide to every common species. Paul Sterry

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Название Collins Complete Guide to British Trees: A Photographic Guide to every common species
Автор произведения Paul Sterry
Жанр Природа и животные
Серия
Издательство Природа и животные
Год выпуска 0
isbn 9780008144593



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5 toothed lobes. Immature and fast-growing trees have deeply cut leaves and long scarlet petioles, whereas older trees have smaller leaves with shallower lobes and shorter pink or green petioles.

imageWILD SERVICE-TREE Sorbus torminalisTo 10cm long with 3–5 pairs of pointed lobes and a sharply toothed margin; basal lobes projecting at right angles, other lobes pointing forwards. Leaves turn to shades of red and russet in autumn.

imageLONDON PLANE Platanus × hispanicaTo 24cm long and mostly 5-lobed and palmate; very variable, however, and degree of lobing may differ greatly.

imageHORSE-CHESTNUT Aesculus hippocastanumLarge, long-stalked and palmate, with up to 7 leaflets, each to 25cm long (central leaflets longest), sharply toothed and elongate-oval; upper surface mostly smooth, lower surface slightly downy.

      COMPOUND LEAVES

imageROWAN Sorbus aucupariaPinnate, composed of 5–8 pairs of toothed leaflets, each one to 6cm long, ovoid and markedly toothed; central rachis rounded near base, and grooved between leaflets.

imageELDER Sambucus nigraUsually with 5–7 (occasionally 9) pairs of leaflets, each one to 12cm long, ovate and pointed with a sharply toothed margin and slightly hairy underside; green in summer but sometimes turning deep plum-red before falling in autumn

imageASH Fraxinus excelsiorPinnate, to 35cm long with a flattened central rachis, which may be hairy, bearing 7–13 ovate-lanceolate, pointed and toothed leaflets, each one up to 12cm long; upper surface usually dark green and lower surface paler with densely hairy midribs.

      NEEDLES AND NEEDLE-LIKE LEAVES

imageCOMMON YEW Taxus baccataFlattened, needle-like and up to 4cm long and 3mm wide, narrowing to a sharp point. Dark glossy green above and paler below with 2 pale yellowish bands. Leaves arising spirally around twig but flattened to lie in a row on either side of twig.

imageDOUGLAS-FIR Pseudotsuga menziesiiNeedles, to 3.5cm long, blunt or slightly pointed, dark green and grooved above, with 2 white bands below.

imageLAWSON’S CYPRESS Chamaecyparis lawsonianaSmall and scale-like, up to 2mm long and flattened along shoot, in opposite pairs, and showing paler colours on underside of shoot. Crushed leaves smell of parsley.

imageLEYLAND CYPRESS × Cupressocyparis leylandiiPointed, scale-like and about 2mm long.

imageSCOTS PINE Pinus sylvestrisNeedles, in bunches of 2, grey-green or blue-green, up to 7cm long, usually twisted with a short point at the tip.

imageCORSICAN PINE Pinus nigra ssp. maritimaSoft, narrow needles, pale green, to 15cm long, often twisted in young trees.

      At first glance, the bark of one tree can look pretty much like that of another. But, as with most things botanical, the more you look the more you will begin to discern similarities between the barks of trees of the same species, and differences between unrelated ones.

      At this point it is worth raising a note of caution. The wise tree enthusiast will accept the fact that some individual trees cannot be identified by bark alone, for a number of reasons. Species such as Ash have bark that looks strikingly different depending on the growing conditions of the tree in question. Furthermore, in many species, the bark of young trees differs from older individuals, usually in being smoother and less rugged. It is also important to remember that the bark chemistry of certain tree species suits the needs of lichens and mosses, some of which are extremely colourful and can mask the true character of the bark. To check true bark colour, it is often necessary to scrutinise the shadiest side of a trunk.

      With the above reservations, reasonably distinctive bark characteristics usually allow most common and widespread trees and certain larger shrubs to be identified with certainty. This ability is particularly valuable for people wishing to undertake conservation management of woodlands in winter and, with this in mind, the following images cover the commonest native and widely naturalised species to be found in Britain.

      TREES

      PEDUNCULATE OAK Quercus robur

      Grey, with shallow ridges in young trees (A), becoming thick and deeply fissured with knobbly ridges in mature trees (B) and gnarled and rugged in ancient trees (C). The white spots in (B) are lichens; the green and blue patches in (C) are lichens and algae.

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       A

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       B

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       C

      SESSILE OAK Quercus petraea

      Greyish brown with shallow reddish fissures when young (A). Most trees acquire deep vertical fissures and knobbly ridges with age, the bark coloured by algae, as here (B), but some have rather shallow scales.

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       A

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       B

      ASH Fraxinus excelsior

      In young trees (A) smooth and pale grey (seen here with whitish lichens and yellowish algae), but in older trees (B) it becomes vertically fissured, although remaining grey-brown; the true colour is often obscured by the large colonies of lichens and mosses that grow well on mature Ashes in unpolluted areas (C).

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       A

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       B

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       C

      SILVER