The reproductive characteristics of natural populations of meadow salsify were monitored between May 1990 and October 1991. Plants in even-aged populations did not produce seeds prior to the second winter and plants in uneven-aged populations died after seed production suggesting that meadow salsify at this site is a monocarpic perennial and not a true biennial. Delayed seed production may enhance abundance of this species by increasing the size of its bud bank. Plants of uneven-aged populations flowered over a range of root crown diameters; the percentage of plants bearing flowers increased with increasing root crown diameters. The minimum root crown diameter at which plants flowered in 1990 and 1991 was 0.2 and 0.6 cm respectively demonstrating that factor(s) other than plant size regulate flowering in this species. Seed production ranged between 100 to 850 seeds per plant. Total number of flower heads per plant and florets per plant were positively correlated with each other and with the root crown diameter. Root crown diameter is, therefore, a good indicator of potential fecundity in meadow salsify. Greater seed production by larger plants may compensate, at least in part, for the high juvenile mortality and longer generation time in this species. The results suggest that prolific seed production and long vegetative survival are important strategies in the maintenance of meadow salsify populations.

Seasonal changes in germination behaviour of meadow salsify seeds buried at different depths, and survivorship of seed and plant populations were investigated. Freshly matured seeds were mixed with sterilized soil, placed into nylon mesh bags, and buried at three soil depths in a meadow salsify-infested rangeland. Two germination peaks were observed: one in the fall, 2 to 3 mo after burial, and a second the following spring. Burial depth affected seed dormancy. The number of seeds with enforced dormancy, and innate or induced dormancy, increased with burial depth in the 1989 cohort, and the number with enforced dormancy increased in the 1990 cohort. Burial depth also affected seed survivorship. The survivorship curves for 1989 and 1990 seed cohorts were not different as indicated by the Logrank test. The seed population was nearly depleted after 9 to 10 mo of burial; less than 3 % of the buried seeds remained viable after 13 mo. About 50% of the plants monitored in a natural meadow salsify population in 1990 died before winter, and an additional 35% died during winter. The mortality of the remaining plants during the second growing season was very low. Only 12% of the 1990 cohort remained in October 1991. Mortality of meadow salsify plants was density-independent.