Sp. Obrien, TIMETABLE OF STIGMATIC RECEPTIVITY AND DEVELOPMENT AND POLLEN-TUBE GROWTH IN CHAMELAUCIUM-UNCINATUM (MYRTACEAE), Australian Journal of Botany, 44(6), 1996, pp. 649-659
The stigma of Chamelaucium uncinatum Schauer is small and unreceptive
at anthesis, but increases in size and becomes fully receptive 7 days
after anthesis. After germination, pollen tubes grow intercellularly t
hrough the stigma and transmitting tissue of the style. Chamelaucium u
ncinatum has a single loculus containing six ovules with axile placent
ation. The transmitting tissue skews to one side within the ovary and
the pollen tubes grow into the placenta via an invagination along one
end of the loculus. Pollen tubes are smooth-walled in the transmitting
tissue of the style and ovary, but within the loculus pollen tubes pr
oduce short side branches. Secondary pollen presentation occurs in C.
uncinatum with the stigmatic region being used as a pollen presenter.
If the self-pollen is not removed from the stigma prior to the onset o
f receptivity self-pollination may occur.