I've been wandering around the Tri-cities area looking for Small-leaved Linden trees, from which I'd like to gather some seeds. Specifically looking for Tilia cordata. Hoping to start some of my own little trees. However, I keep coming across trees that the "Seek" app on my phone identifies as Katsura trees. Both trees have heart shaped leaves and little brown nutlets. They are so similar looking that even the phone app mixes them up often. So I'm here to ask: how to differentiate these trees? Looking from afar, do they take on different shapes (e.g., one is rounded while the other is triangular)? Is the bark different? Arrangement of leaves? etc.?
Tilia leaf arrangement is alternate; flowers have male and female parts which are attached to a flat finger-shaped bract. Katsura (Cercidiphyllum) leaf arrangement is opposite; it has male and female flowers growing on separate trees before the leaves appear. For Vancouver locations, you can do a query at Public trees — City of Vancouver Open Data Portal. Enter Tilia cordata, click the map button to view the locations. You need to have a good enough idea that you can tell if the city has them mis-identified. I don't think the city will mix up those two genera though, just maybe the Tilia species.
Seen together the veins are arranged differently. Tilia cordata..leaves are alternate. While Cercidiphyllum japonica are opposite.
Additionally Small-leaved Lime leaves are oblique with an asymmetrical base, not symmetrical the way Katsura leaves are.