Common Groundsel or old-man-in-the-Spring [Senecio vulgaris] found at Fletcher Park on 17 April 2016 and probably 16 March 2013. It’s a member of the Aster (Asteraceae or Compositae) family and Newcomb’s Wildflower Guide, pages 416-417 states that it is “a weed of cultivated land and waste places,” and it blooms from Spring to Fall. The USDA web site has its primary name as old-man-in-the-Spring. Other names listed in An Illustrated Flora of the Northern United States and Canada, Vol III, are grinsel, simson, birdseed, and chickenweed.
USDA Plants Listing: Senecio vulgaris