As regular visitors will know, Dr M is currently teaching British tree identification in his Vegetation Survey and Assessment module on the MSc Plant Diversity and MSc Species Identification and Survey Skills.
Amongst the features which help in putting a name to a tree include the twigs, leaves and buds.
Buds come in all shapes and sizes and colours, all can be helpful for ID.
Several common British tree genera have rather characteristically coloured buds.
For example: Lime (Tilia) has reddish buds, Sycamore (Acer) greenish buds and Ash (Fraxinus) blackish buds.
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- Acer pseudoplatanus (Sycamore) green, round, opposite buds
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- Fraxinus excelsior (Ash) black buds
Impromptu pub quiz question: which country has red, green and black in its National flag? Answer at the bottom of this post…
OK, thanks for the digression Dr M, where were we? Ah yes, the colour of buds…
Of course there are other characters which identify these trees too and its never a good idea to rely on just one character for an accurate ID.
So, Sycamore buds have a number of bud scales while Ash and Lime have few.
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- Tilia (Lime) alternate, simple, cordate and serrated leaves
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- Acer (Sycamore) opposite, simple and palmately lobed leaves
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- Fraxinus (Ash) opposite, compound and pinnately dividedleaves
Equally, while Ash has compound (pinnate) leaves, Sycamore has simple, palmately lobed leaves and lime has simple, entire (but serrated), heart-shaped (cordate) leaves.
Also both Ash and Sycamore have opposite leaves while Lime has alternate leaves.
So bud colour combined with other features of the buds and leaves help ID these 3 familiar genera.
Of course more work is needed to separate out the related species in these genera, both native and introduced, but that’s for another time!
Now was there something else?
Ah yes…
Dr M’s impromptu pub quiz answer: Red, Green and Black feature in the flag of Malawi.
Image credit: http://commons.wikimedia.org/wiki/File:Flag-map_of_Malawi.svg
October 15, 2013
