Key points are not available for this paper at this time.
Olle Pellmyr, The Pollination Biology of Actaea pachypoda and A. rubra (Including A. erythrocarpa) in Northern Michigan and Finland, Bulletin of the Torrey Botanical Club, Vol. 112, No. 3 (Jul. - Sep., 1985), pp. 265-273
Olle Pellmyr (Mon,) studied this question.