This plant is similar to Fimbristylis dichotoma, but different enough to raise doubts about that species as a correct ID. David Albrecht at the CSIRO wants to get a correct ID and will follow it up. Michael Bedingfield has supplied him with 2 sets of specimens. In his latest communication (20 Sept 2018) David said: "I think Fimbristylis aff. dichotoma is the best name to use for it at this stage. I’ll try to get out to the site this season and collect a small amount of live material. If I can get it going and keep water up to it over summer we might be able to get some fully developed mature fruits, which with help with the identification."
Fimbristylis sp. aff. dichotoma is listed in the following regions:
Canberra & Southern Tablelands