Variation in dormancy among populations of the fire-ephemeral flannel flower, Actinotus helianthi

Nathan Emery, Catherine Offord, Glenda Wardle, Murray Henwood, Robyn Overall

Abstract


Dormancy is a necessary mechanism to prevent seeds from germinating during unfavourable external environmental conditions. For the Sydney Flannel Flower (Actinotus helianthi Labill.) it is not clear how the environment influences the erratic variation experienced in published germination trials. This study examined differences in dormancy and viability between several wild populations of Actinotus helianthi. Mature seeds were collected from four populations across the Greater Sydney region. Germination of seeds was assessed at 15oC and seeds were pre-treated with deionised water or 1% smoke water (1% has been previously demonstrated to improve germination in Actinotus leucocephalus). Poor viability ranging from 40% to 58% was identified across all populations, producing low numbers of germinated seeds. Significant variation in germination percentage between populations was exhibited in seeds treated with smoke water. Seed from Flannel Flower populations should be collected, stored and germinated separately. The variability recorded between populations is most likely an adaptive response to the fire history of the area, giving varying levels of smoke sensitivity.

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