Saturday, October 23, 2010

A Tree-Spotter's Guide to Fruits and Seeds: Part 3

European larch Larix europaea is our only deciduous conifer so it should be easy to identify, but there are two Larch species grown in Britain and a hybrid between them, so it's sometimes tricky to identify a tree unequivocally. Unlike their needles, larch cones stay attached to the twigs for several years and this one, with wavy-edged cone scales that hardly curve outwards at the tip, is L. europaea. European larch has elegant pendulous branches that can sweep down to ground level and if it's given space to grow it will become a graceful specimen tree; sadly, most are destined to grown at close spacings in plantations.

Faster-growing Japanese larch Larix kaempferi produces cones with scales that are emphatically curled outwards and downwards at the rim. The extremely vigorous hybrid between L. europaea and L. kaempferi, known as Dunkeld larch L. x eurolepis has cones that are similar but the lip curls outwards without curving downwards .... but, when this hybrid then crosses with L. kaempferi it all gets very confusing....
When I was a kid, my parents took me Christmas shopping in Charlotte Street market in Portsmouth, where there were hot chestnut sellers on street corners who would serve you up a brown paper bag full of smouldering chestnuts that you had to toss from hand to hand until they were cool enough to peel. They probably imported their chestnuts from southern France, or Spain where the tree is native. Sweet chestnut Castanea sativa was brought to England by the Romans, who recognised the value of its nuts and coppiced timber. It needs a good summer to produce chestnuts that are worth roasting here in County Durham - and this hasn't been one of them. Most British trees produce several small nuts per spiny fruit, rather than one large one.


Autumn, when acorns are ripening,  is the best time to identify our two native oak species. The sessile or Durmast oak Quercus petraea bears acorns that have little or no stalk.


English or pedunculate oak Quercus robur acorns dangle from a long stalk (peduncle). Occasionally the two species form hybrids, bearing acorns on short stalks. Oaks, like beech trees, tend to bear heavy crops of seeds on alternate years ('mast' years). It's a mast year for oaks in Durham city this year and they are lying thick on the ground, attracting flocks of pigeons and a lot of jays that are carrying them away to bury for winter emergency rations - if they ever remember where they have buried them. Last year there was hardly an acorn to be found under the same trees.

 

Elder Sambucus nigra berries are popular for making home-made wine but they also have a history of use as a source of dye. Freshly dyed fabric tends towards a rich brown but addition of metal salts like aluminium, chrome and copper as mordants produces subtler shades that vary from umber to blue, violet, grey and through to black, although they all tend to fade after a while in bright light.

For more posts on tree ID click here

6 comments:

  1. Another of your super pieces on tree fruits and seed, Phil, thanks. Lovely acorns and a super bunch of elderberries.

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  2. I'm really enjoying this series Phil.
    Excellent.

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  3. It's a pleasure searching out the specimens to photograph, Adrian..

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  4. It seems to be really good year for lederberries around here Emma - the trees are weighed down with them..

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