Floral Biology and Self-Incompatibility in Some Australian Mistletoes of the Genus Amyema (Loranthaceae)

Abstract

Facultative cleistogamy has not been found In some Austrahan Amyema spp , and the stigma does not functlon in pollen presentation at anthesis. Wlthin mature flower buds self-polllnatlon is prevented by morphological and physiological barriers, a protandrous condition largely prevents mechanical or zoophilous self-pollination In vitro pollination experiments revealed that xenogamous crosses are most successful In the production of pollen tubes in the style although geitonogamy may act as a 'fail safe mechanism' at varying levels under natural condltlons in A miquelii (Lehm, ex Miq) Van Tiegh, A. miraculosum (Miq ) Van Tiegh and A. penduium (Sieber ex Spreng ) Van Tiegh. Of the four species studied, A. quandang (Lindl ) Van Tiegh had the highest levels of self-compatibility.