In message om, Simon
W writes
Hi all,

I need some help identifying the kind of tree outside my house planted
by the city several years ago.

More importantly I'd like to know what those ugly "red spikes" on some
of the leaves are. Are they mite galls? If so, how to get rid of them?
About 20% of the leaves have these spikes.

Here are some pictures I just took today:

Entire tree:
http://poboxes.podzone.org/tmp/tree_overall.jpg

Leaves close-up:
http://poboxes.podzone.org/tmp/good_leaves.jpg

Spikes:
http://poboxes.podzone.org/tmp/spikes1.jpg
http://poboxes.podzone.org/tmp/spikes2.jpg
http://poboxes.podzone.org/tmp/spikes3.jpg
http://poboxes.podzone.org/tmp/spikes4.jpg

Thanks and have a nice day.

It's a lime (linden, basswood). I don't recognise the species, but from
the white underside to the leaf (and it not looking like Tilia
tomentosa) I'd guess at one of the forms of Tilia americana var
heterophylla. The third "white" lime is Tilia oliveri.

http://www.malvaceae.info/Genera/Tilia/gallery.html

The "spikes" are nail galls. According to the RHS (Royal Horticultural
Society, UK) you can't get rid of them, but they're harmless and should
be tolerated.

http://www.rhs.org.uk/advice/profile..._gall_mite.asp
--
Stewart Robert Hinsley