It's much harder to notice when the flowers are similar in colour, and also when the two kinds of flowers appear at different times, and the mazzard flowers are not showy. That's what's so nice about the 'Kanzan' two-tones - they really are two-tone. Yes, there is a start time when the mazzard suckers didn't used to be there and now here's a new one. But for it to get that size, it's been there for several years.
Another two-tone to add. This is on the north east corner of Taylor Way as it meets Stevens Drive in West Vancouver.
Since learning about these two tone trees I can't stop seeing them. Two Kanzan trees on Glenmore Drive in West Vancouver but only one is two tone, so far.
In that second photo, you can easily see the sepals curled back against the calyx tube (on the back of the flowers). That is characteristic of Prunus avium, not characteristic of any of the ornamental cherries except for avium 'Plena' (the double-flowered avium cultivar). So that is a pretty reliable way to identify a tree that is entirely mazzard/sweet cherry.
