The suckering of aspen (Populus tremuliodes Michx.) as a highly effective means of vegetative propagation is well known and has been widely studied (Baker 1918; Day 1944; Maini 1967; Schier 1974). Less is known about seed propagation, sometimes viewed as having only minor importance because early research (Baker 1918) had indicated that rare seedling establishment was due to low or nonexistent germinability.
United States Department of Agriculture, Forest Service, "Quaking Aspen - Seed Germination and Early Seedling Growth" (1979). Forestry. Paper 28.