Seasonality of seed production and germination trends of Fumana ericoides (Cistaceae) in the west semiarid Mediterranean region

Fumana ericoides, a south Mediterranean shrub, flowers twice a year, in spring and in autumn. Its seeds exhibited marked variation in the degree of dormancy, attributed to an impermeable seed coat, ranging from very low initial dormancy (1.7%) in seeds that matured in winter to total dormancy (100%) in those that matured in late spring/early summer. The level of dormancy increased rapidly with time in the first three months in winter-matured seeds, peaking at 75.5%; decreased with time in the second category; and reached a comparable level in both (25.0% and 23.2%, respectively) after nine months and three months, respectively. From then on, changes in dormancy were similar: seeds that had matured in winter reached the second lowest level of dormancy (28.4%) after 24 months and those that had matured in late spring/early summer seeds after 19 months (32.7%). In every case, the dormancy was at its lowest in autumn–winter, the most favourable season for germination and for the survival of seedlings.