Seed germination ecophysiology of the woodland herb Asarum canadense.

In N-central Kentucky, flowering begins in mid- to late April, and seeds are mature by mid-June. Seeds exhibit epicotyl dormancy. Radicle dormancy is broken by high summer temperatures, shoot dormancy is broken by low winter temperatures. Thus, radicles emerge from seeds during autumn, and cotyledons emerge the following spring. This temporal separation of radicle and cotyledon emergence may be of adaptive significance in deciduous woodland herbs.-from Authors