FLOWERING AND FRUITING PHENOLOGY AND BREEDING SYSTEM OF CISTUS-ALBIDUS L

The flowering and fruiting phenology and breeding system of Cistus alb idus L. are studied. Four phases are established for the development o f the flower, which remains open for a period of less than 14 hrs, alt hough this time-span can be further reduced if environmental condition s are unfavourable. Only 65.6% flowers develop ripe fruits, the greate st losses occurring in the change from flower to unripe fruit. it is a xenogamous species with a P/O ratio of 5.426 +/- 816. Experimentally, fruits may be formed by autogamy through manual pollination, although this does not occur spontaneously. There is recognition by the plant of its own pollen tube, which reduced the production of fruits by auto gamy. This mechanism can be considered as cryptic self-incompatibility system.