Tuesday, August 16, 2011

Bark Shedding Trees: Plane Trees

Plane Trees: first becoming aware of these wonderfully trunk- patterned trees when I was a student in Chelsea Art School, I just knew them as "Plane trees". When I went to Santa Monica, I suddenly heard them called "Sycamores" or "London Planetrees". In fact, they are all part of the Platanus family. Platanus occidentalis is the native North American Plane while Platanus x acerifolia is the London plane tree, actually a long established clone (more than 300 years ago) between the North American and Oriental planes. There are numerous variations within this species, while it is thought the most common ones in London are Platanus x acerifolia 'Pyramidalis'.

These are the ones I am writing about. The ground in the local parks- Valentines and South Park- is at present littered with the debris of cast off bark as the trees metamorphis into serpents. Opinions differ about the cause of this 'sloughing' of the bark- from a means of discarding burrowing insects and fungal deceases / a means for the tree to conduct photosynthesis via the exposed to the sun bare trunk, rather than-or as well as- through the leaves / to the fact that the bark is rigid, not elastic enough to stretch with the tree's growth. Whatever the reason, the effect is visually amazing- fantastic, jigsaw-like patterns being formed by the exfoliating bark.

The trunks of some of the older trees are gnarled and knobbly:

Then, when you look up into the branches, you see the exposed bright virgin wood and the bright coloured patterns where the bark has been shed from the younger wood:

This is when you really start thinking of Pythons and snake pits....

The whole process reminds me yet again of my childhood on the moors of Aberdeenshire. There we would often see Adders basking in the sunshine- and in the Spring they would shed their skins (so exciting to find these fragile, scaley tissues) and vibrant, shiney green, yellow and black scales would be exposed...

And here are some of the bark 'sculptures' below the trees:

This next image is of a more typical, younger tree, displaying the camouflage-like patterns and colours:

In fact- sad to say, but interesting nonetheless- military camouflages have been based on this bark; below is the German design for the SS, Platanenmuster-"Plane-tree pattern" (1937-1942): first, Spring/Summer colours:

Secondly, the Autumn variation:

Before leaving the subject, I will just show images of a couple of other prolific bark-shedders that I have seen in the last couple of weeks. Here is the extraordinary Paperbark Maple- an Aceraceae, Acer griseum. The first two photos are of one that I saw in Leamington Spa's Jephson Gardens:

And this next tree- and its bark on the ground- I saw in Hidcote's gardens. I read that in the Autumn the leaves turn a vibrant scarlet- what a sight that must be with the colour of the bark!

Finally, back to Birch trees, many varieties of which also shed their skins; this, too, I saw at Hidcote:


Georgia said...

Yay, you are back, with tree posts. I like this series on bark.
-- http://localecologist.blogspot.com


Thanks Georgia- good to hear from you
! have just been enjoying localecologist...

jani said...

I just planted an "Exclamation! London Planetree" in May and was surprised to see the bark exfoliating already in June! It's beautiful. I wasn't sure if the shedding was due to the move or if this is the time of year it will happen every year? Judging from your very well documented article I believe this is the normal time for it to happen.
Thank you for all the photos.