As far as I know there is only one group of aspens (Populus tremula L.) in the parish - along the Green Lane Nature Trail that we and the local schoolchildren planted up about 15 years ago on College ground for the National Westminster Countryside Initiative!
The long bilaterally flattened petioles wave about in the breeze, encouraging the leaves to flop from side to side and so give the "trembling" look (and rustling sound) of the foliage characteristic of this and some other species and cultivars of poplar (or as the Americans say, cottonwoods). In light or no winds the leaves hold rigidly still, in complete and rather spooky contrast.
The patch we have seems to be suckering densely about the base of a few older trees, which we may have planted with BTCV encouragement all those years ago.
The leaves are all a good mid-green at present but should eventually be changing to their beautiful golden autumn colours, and showing well by October. The petioles and venation is a characteristic poplar yellow-green, but one point to notice is the maturity of the twigs. Already, by mid-August, the twig bark of this year's growth has hardened to a good solid-looking olive brown, actually darker than the more yellowy previous year's growth, particularly on the underside of the shoot. This is a bit of a conundrum, as how could twig bark get lighter over time? The buds are also already apparently well-formed, particularly the terminal ones, which already look as if they have entered a resting phase, although they are still a bit small (c. 6 mm. on the tip). In fact our aspen already looks ready for winter. Perhaps this possible early preparation for winter is one reason that aspen is so common in Scotland and can even grow well above the Artic Circle in Norway, where very few other decidous flowering trees occur - a very tough customer indeed.
Axillary buds laterally compressed and pointed, 3-4 mm long, greenish with brown tips, terminal bud more chunky, although still only 6 mm long, greenish and brown over scales.
Our leaves don't seem to resemble sucker leaves at all, as described by BSBI, but appear completely characteristic of the standard trees. Are our "suckers" really seedlings I wonder? Leaf blade up to 8 cm long by 7 cm wide, petiole a matching 8 cm long, larger than as in Mitchell, but OK by BSBI. 6 - 12 pairs of teeth on the rounded slightly crinkled leaf margins. Leaf tips generally drawn into somewhat acuminate points, so that the toothed margin and pointed leaf tip contrast unusually with the overall rounded leaf outline. Beautiful trees!
They aren't so common in the Southeast of England, although there is a well-known tree on the boggy soil of Hothfield Heaths near Ashford in SE Kent. A BTCV connection perhaps?
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