No abstract

The diverse floral structures of Australian Myrtaceae are discussed in relation to pollination biology, breeding systems, and ecological and evolutionary relationships. Although the reproductive biology of Eucalyptus has been studied widely, little is known about many of the other genera. The review concludes that additional work is needed on aspects of flower structure, pollination biota, late acting self-incompatibility, secondary pollen presentation and reproductive success.

Flowers of Thryptomene calycina contain two types of secretory tissue. Nectaries of the floral tube secrete a nectar rich in fructose and glucose, probably through the numerous stomata in the epidermis. The secretory cells are densely packed and have few vascular connections. The five anther connectives each terminate in a gland, which at anthesis contains large, thin-walled cells. The gland contains a hydrophobic material which stains positively for lipids and probably contains phenolics. This material is secreted through a pore at the end of the gland where it collects and mixes with pollen to form a food source for insects. This dual secretion of food materials would ensure that a wide range of pollinating insects visit the flowers.

No abstract

Seeds from two subalpine populations of E. pauciflora stored for 1 year were completely dormant and required stratification to induce germination. Fresh seeds from the same populations were partially dormant. Seeds from a third subalpine population whether fresh or stored were only partially dormant. Seeds from two lowland populations were not dormant, although stratification did reduce the time taken to complete germination. The optimum germination temperature for all populations was near 20°C. Temperatures above 25°C induced a secondary dormancy in stratified seeds from two of the subalpine populations.