Actaea racemosa and racemes

I joined my daughter on a one-day trip to a Girl Scout camp.  While the girls were climbing the rock wall, I was looking for wildflowers in the lovely forest there.  We saw many large flowering Actaea racemosa whose common name is Black Cohosh and Black Snakeroot.  This plant has a long (6 inches or more) raceme of white flowers.  The leaves are divided (compound) and most of the leaves arise from the base of the plant, but some are alternate along the stem.  The mass of multiple stamens spewing out of each flower give you a clue to the plant family - a basil Eudicot, Rununculaceae.

This plant is in the same genus as White Baneberry (Doll's Eye) which is a distinctive poisonous plant of Pennsylvania.

As I tried to key out this plant - I had to distinguish between racemes and spikes.  In a raceme, each flower has a stem or stalk.  In a spike, the flowers are stalkless. For more information visit this wikipedia page:   http://en.wikipedia.org/wiki/Spike_(botany)

Here are some pictures of this interesting plant!