The appearance of 17 cones on one of my 4 Wollemias - male as pointed out to me by Mark Taylor - spurned me on to collect some more information about the breeding system of Wollemia nobilis. Because of the lack of reproductive material the study of how Wollemias breed has been difficult so far. As Mark already wrote earlier on this blog the breeding system is monoecious (i.e. male and female cones are borne on the same tree). The male cones are seen on both adult and juvenile leaf branches, the latter only in conditions of high light. Field observations indicate that female cones are only produced on adult fase leaf branches which occur above the rainforest canopy layer. I understand that in the UK female cones so far have only occurred on Wollemias in Kew Gardens. Male cones appear in early to mid summer and mature in spring when pollen is shed. Female cones appear in mid to late summer and are pollinated in the following spring. Fertilisation occurs approximately one year after pollination, several months prior to seed cone maturation, in late summer and early autumn when seed and bract-scale are shed. Male cones grow to 10.9 cm long and are 19 mm in diameter. Female cones grow to 5-8 cm long in diameter. Seeds are pale brown and 4-6 mm wide, including the wing. The position of the cones is at the tip of the branches. The female cone is always above a male cone. After cones mature the branches continue to grow vegetatively. Although Wollemia is able to produce viable seed, there is no detectable genetic variation in its population and it appears to be clonal. It is therefore very vulnerable. One nasty virus or fungus and Wollemia may be gone forever. Small wonder that the location of the tiny wild remnant is kept strictly secret. Generally, less than 10% of the approximately 250 ovules in female cones develop into viable seeds. Some cones were observed to have up to 22% viable seeds. The seeds are light and winged and in the existing stands they are most likely dispersed by the wind. Seeds that survive winter germinate quickly with an optimal temperature range of 24-30 degrees centigrade. I have sent Mark some illustrations and pictures of both male and female cones for the photograph section to make it easier for people to see the difference. I will keep a close eye on my Wollemias and look forward to hearing from more fellow Wollemmia enthusiasts about cones appearing on their trees, especially female ones. Ben Alofs