A contribution to the germination ecology of Floerkea proserpinacoides (Limnanthaceae)

Seeds of this spring ephemeral were dormant at maturity in mid to late May. Fresh seeds sown on soil in a non-temperature-controlled greenhouse in early June germinated from late December through mid February. Between December 22 and January 20, when mean daily maximum and minimum temperatures were 6.3 and 0.0°C, respectively, 78% of seeds germinated. Fresh seeds were placed at 30/15°C (warm stratification) for 0-12 wk and then moved to 5°C (cold stratification). Seeds either remained at 5°C or after 0-12 wk were moved to 15.6°C. Cold but not warm stratification is required to break dormancy, but warm stratification given prior to cold stratification decreased the length of the cold stratification period required to break dormancy. Seeds receiving no warm stratification reached 50% germination during the 19th week of cold stratification; seeds given a 12-wk warm stratification pretreatment reached 50% germination during the 8th week after transfer to 5°C. -from Authors