GERMINATION ECOLOGY OF THE FACULTATIVE BIENNIAL ARABIS-LAEVIGATA VARIETY LAEVIGATA

This facultative biennial grows mostly in rocky woodlands in E North America, and its seeds have non-deep physiological dormancy. Seeds mature in June, and dispersal lasts for up to 19 mo. Germination occurs in March and April; seeds that fail to germinate in spring become part of a persistent seed bank. Freshly matured seeds were either dormant or conditionally dormant; they germinated to a maximum of 38%, at 30/15°C in light. Seeds became nondormant during stratification at 5°C. Freshly matured, dormant seeds buried in soil in a nonheated greenhouse became nondormant during winter and re-entered dormancy or conditional dormancy during summer, which was broken the following winter. -from Authors