past posts about the tree, it looks like the warm spring this year may have hastened the opening of its buds, but not by much.
The relative rareness of the tree in the wild suggests this very conservative strategy of remaining bare five or six months of the year has not proved very successful, but it probably helps these trees survive freak storms like the snow storm that hit Princeton in late October last year.
Internet sources mention it as highly compatible for planting next to passive solar homes, since it only obstructs the sun during the warmest months, and also as a tree associated with historic settlements. Wikipedia mentions a few of these trees in the gardens at Mount Vernon. The grove across the street from me grow on the original farmstead of Joseph Stockton, where Thomas Jefferson is said to have stayed on occasion.
To the left and lower right in the photo are Norway Maples fully leafed out.