A puzzler (for me at least) from this morning aling the canal at Westbourne Green, London.
Struck me as an alder but not really adding up for me. No cones visible.
Any help appreciated.
I'd go for green alder, Alnus viridis
The leaves should have 8-9 pairs of veins (I think you can ignore the tiny ones) and the petiole should be grooved.
It is not a common tree; actually it is usually more of a shrub than a tree. How big and how shrubby/treey was yours?
You'll note from the description in the link above, that "The flowers are catkins, appear late in spring after the leaves emerge (unlike other alders which flower before leafing out)"
I suggest you do a bit more digging/comparing. Please post to let us know what you think.
It's actually a reasonably substantial tree (see attached pics). Petioles show a slight groove but macro focus on my camera is rubbish so no pic of that feature.
Any further thoughts very welcome.
Thanks for the further photos & info.
Frankly, I'm stumped.
I have considered the other genera in the Betulaceae; and I am sure it is within Alnus.
Within Alnus, I have considered:
alnobetula, cordata, crispa, fauriei, glutinosa, hirsuta, japonica, maritima, maximowiczii,
oregona, orientalis, pendula, Alnus rhombifolia, rubra, rugosa, serrulata, sieboldiana, tenuifolia, x mayrii.
The leaves are a fairly good fit for Alnus viridis, but the habit (tree not shrub) is definitely wrong.
There is a hint of A. maximowiczii (which used to be considered a subspecies of A. viridis, and which is not surprisingly therefore often multistemmed) - see http://www.fobbg.co.uk/Alnusmaximo.html
Alnus incana fits in some respects, but the middle of the sides of the edges of the leaves should have distinct lobes (as well as finer toothing) - as shown here - http://luirig.altervista.org/photos-search/index.php?title=Alnus+incana and http://www.forestryimages.org/browse/detail.cfm?imgnum=1379013
Many species of alder have subspecies and forms; maybe it is one of those, eg. Alnus incana subsp. kolaensis. I don't have sufficient information to decide.
But there are also other species of Alnus, for which I don't have sufficient information:
acuminata, cremastogyne, × elliptica, × fallacina, ferdinandi-coburgii, firma, glutipes,
henryi, lanata, mandshurica, nitida, oblongifolia, paniculata, subcordata, trabeculosa, vermicularis, and some other Japanese species.
(but I have been using books, too)
Suggestion: Westbourne Green Public Open Space is managed by the Westminster Parks Service; try asking there (Westminster City Council contacts - https://www.westminster.gov.uk/contact). If you get an answer, from there or anywhere else, please let us know. Sorry not to be able to give you an ID on this occasion.
many thanks for looking into this si extensively. A great help.
I'll take up your suggestion and see if I can come up with any info from Westminster. Failing that, I'll secure more photos and see if Kew can help. Either way, should I get a firm identification I'll be sure to let you know.