Hello to all plant people. I'm a new participant who has stumbled onto this forum while looking at the Maple Society website. I'm an amateur interested in native species of the PNW. I'm looking for a set of distinctive characteristics for identifying Acer circinatum vs. Acer japonicum and Acer pseudosieboldianum. Wikipedia says it is difficult to tell them apart since they are closely related species. I've been thinking that the 2-seeded samara of A. circinatum may be distinctive, especially the angle between the "wings". While researching on the Web, I bumped into a partial download of the identification book What Maple is That? by Peter Gregory and Hugh Angus, but it did not include the section on fruits. I've been unable to find the entire book at my local library or online. However I saw that the book was associated with the Maple Society. I looked there, didn't find it and so here I am. I'd be grateful for any help on making those IDs. Thanks for any help or ideas.