Here are some tree shots I just took, increasingly closer up:
This spring of 2012 in the northeast is the earliest one I can remember. In the nearly three decades that my redbuds have graced my front yard, they never have flowered in March. Not one time. And this year it was a full week prior to the end of the month.
The link to Ultrarunning is that trees are a major factor in our running. You get to know tree habits and preferences. The Eastern Redbud is a smallish tree, more of an edge species than the deep woods. So while I might see some on, say, an Appalachian Trail run, it's not really a common species in the ridge top habitat.
You may want to check out my previous redbud posts here and here. It's pretty obvious that I am smitten with this tree.