Green Violet, Hybanthus concolor
Violaceae or Violet Family

Plant to about three feet tall, with glossy green oval leaves tapering at both ends, furry stems, and small green flowers dangling below the leaves, mostly in pairs.  A single known population in Wildwood grows on rocks above Connelly's Run near the south bridge on the Riverway.

Flowers are distinctive, but it is hard to identify if not in flower, and it is likely to be overlooked anyway.

More information.