LABILE SEX EXPRESSION AND DYNAMICS OF GENDER IN THYMELAEA-HIRSUTA

Gender phenotypes of Thymelaea hirsuta (L.) Endl, were recorded at fiv e natural populations during regular visits occurring 3-6 times per ye ar over a period of 3-6 years. Plant gender was quantified and calcula ted over all seasons and all reproductive sessions. Two major categori es of sex expression were apparent: plants were either stable in their sex expression through all periods of observation, across all reprodu ctive sessions (individuals were either a male or a female for the tot ality of observations), or individuals were sexually labile to varying degrees. Gender-labile individuals were further categorized into nine phenotypes. Site was significantly associated with the frequency of s ex forms. Labile sex expression is discussed in terms of niche separat ion and the sex ratio of both individuals and flowers.