hort.net Seasonal photo, (c) 2006 Christopher P. Lindsey, All Rights Reserved: do not copy
articles | gallery of plants | blog | tech blog | plant profiles | patents | mailing lists | top stories | links | shorturl service | tom clothier's archive0
Gallery of Plants
Tech Blog
Plant Profiles
Mailing Lists
    Search ALL lists
    Search help
    Subscription info
Top Stories
sHORTurl service
Tom Clothier's Archive
 Top Stories
Disease could hit Britain's trees hard

Ten of the best snowdrop cultivars

Plant protein database helps identify plant gene functions

Dendroclimatologists record history through trees

Potato beetle could be thwarted through gene manipulation

Hawaii expands coffee farm quarantine

Study explains flower petal loss

Unauthorized use of a plant doesn't invalidate it's patent

RSS story archive

Leaf Spot and Pollution

If I remember my mycology courses correctly (we are way back in the
early history of England here), the impact of the extreme coal-based
smogs in London up until about the early 1950's was to prevent the
growth of most trees in the area.  The only tree that really survived
successfully was the plane tree [Platanus occidentalis and orientalis
and their hybrid acerifolia).  In the US, these trees are usually called
sycamores, which is a different tree (Acer) in England.  The reason the
plane tree survived was its habit of shedding its bark in sheets and,
thus, removing the soot that accumulated.  At the same time, this tree
was host to a leaf spot, which was apparent because it cause large black
spots to appear on the leaves.  That is, except in areas of heavy smog
where the leaf spot was absent.  It was believed that, the high sulphur
content in the coal fumes killed the fungus.  Of course, it killed lots
of Cockneys as well and those that could afford it moved out of London
and eventually arrived in places like Canada.

I have looked through my library to find the actual reference for this
information to no avail.  I do have an account of the plane tree/smog
story which, by the way, also mentions that one of the herbs to survive
the air pollution were the irises because they had thick cuticles on the
leaves (London's Natural History by R.S.R. Fitter 1945).

Ian, a cockney in smog-free Ottawa.

 © 1995-2015 Mallorn Computing, Inc.All Rights Reserved.
Our Privacy Statement
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index