A tree I love to hate is the Japanese Tree Lilac (Syringa reticulata). A leaf is illustrated in Figure 1. It is unobtrusive during most of the year, but in early June, it has large white flowers that smell like a scent they use for toilet paper.
Figure 1. Syringa reticulata leaf. Upper side is on left.
I started this post on Friday, but was too busy to complete it.