Resulting fractions of aspirating a Gahnia radula collection harvested from South Hobart. Empty fruits had a higher likelihood of being grey, whereas full fruits were a mid to dark brown.Gahnia radula is an important understorey species and one of two food plants for the rare Chistola Skipper butterfly. Collecting of viable seed of Gahnia radula has proven to be problematic and have presented a serious obstacle for restoration/re-vegetation activities. The reasons for the poor seed set is as yet unknown. The collection is currently under testing at the RTBG seedbank but early indications are that this species is also deeply dormant.
Viable collection of Gahnia radula (thatch sawsedge) achenes after passing through a seed aspirator. Image shows heavy and light fractions produced by the aspirator's winnowing process. Collection harvested in late January from Hobart, Tasmania.Colour differences are often poor indicators of seed quality, but for this collection at least, viable fruits tended to be brown to tan whereas empty fruits were mostly grey.More study is required but it is possible that this species takes over a year for the seed to develop.
