in Vancouver, British Columbia, Canada - Davidsonia

Davidsonia 18:2 63or cordate to cuneate. Leaf size is 10-15 x 5-8 cm (4-6 x 1.9-3.1in) onmature flowering specimens, while on vigorous trees on moist sites theleaves often resemble those of Populus, often reaching 24-30 x 6-8cm(9.4-11.8 x 2.3-3.1in). The leaf margins are set with regular, 1mm pegliketeeth and have conspicuous, in-rolled flanges. Petiole length rangesfrom 2-5cm (0.8-2in) and the petiole curves downwards where it attacheswith the leaf-blade. There is a pair of small glands at the junctionof the leaf blade and petiole. These are pinkish in color (similar to thevegetative buds) and resemble those found in Populus. Leaves fall greenin the late autumn (November) if weather conditions remain frost-free.We have never recorded any autumn colour.FlowersPlants are remarkably variable with respect to flowering. Dr. QuentinCronk and his students have been studying the phylogeny of Carriereaand the genomics of the Salicaceae, and they have shed some lighton this sexual plasticity. Several genera in Flacourtiaceae (a considerablenumber of flacourts are now placed within the Salicaceae, (Cronk, 2005)including Carrierea, are functionally dioecious, yet sporadic occurrencesof monecious and hermaphrodite individuals occur. The fertile seedpodsof hermaphrodite trees are generally located at the terminal positionof the panicle. The same morphology occurs in the closely relatedgenus Idesia. It is interesting to speculate about the adaptive advantageof this wide range of sexual options. Both monoecy and especiallydioecy inhibit inbreeding (Quentin Cronk, pers. comm., 2005), whichcan have negative effects on a species’ long-term viability, but hermaphroditicbehavior may give the plant survival benefits, when geographicisolation, climatic stress or physical disturbances pose powerfulnatural dangers to their continuance.Individual flowers are borne in erect or spreading inflorescenceson lax terminal shoots (Figure 4). The flower masses resemble a candelabra.Wilson described them as “…curiously-shaped, waxy-whiteflowers borne in erect panicles” (Wilson, 1913. page 173). The rose-redrachis of the panicles is a most attractive foil for the pale flowers. Upto 10 flowers are produced, each with five heart-shaped, rugose sepals,which functionally replace normal petals. Flower colour varies from