Thank you all for your replies!
I agree, the laburnum does seem to resemble Laurelin very well and it looks nice as well.
As far as Telperion is concerned I read on a German Tolkien wiki that its leaves were dark-green on the top and silver-grey on the bottom. I don't know if this detail matches the poplar or one of the cherry trees. Still some good ideas for this as well!
And no, we don't have any animals around so toxic trees are ok as long as they look good.
