@MatthewFrawley . Good evening ! in the first photograph here, please give an estimate of how wide the culm lamina is just above your finger holding it and below the shown structure of the inflorescence.
I am tentatively suggesting Lepidosperma sieberi, and require more evidences to check this, let alone to confirm this . Confer with superficially similar Lepidosperma concavum which this does not appear to identify to . Confer with superficially similar Lepidosperma prospectum which this does not appear to identify to .
One of the more recent high quality scholarly references –i recommend reading for many people here in NatureMapr–; with the formal description of Lepidosperma prospectum; more wonderful information; and some taxonomic information on its superficially similar species: Lepidosperma concavum, Lepidosperma sieberi and Lepidosperma latens . https://openjournals.library.sydney.edu.au/TEL/article/view/14879 .
Please use your first hand experience with this plant to assist with answering this question (from the Flora of NSW online PlantNet key to Lepidosperma spp.):
• Culms with central biconvex ridge and thin, broad, flattened margins, 5–20 mm wide – Lepidosperma gladiatum
• Culms flat, concavo-convex, or convex on 1 face and flat on the other, 3–7 [8] mm wide – 20 ... Lepidosperma concavum ... Lepidosperma latens ... [presumably here also when this key gets updated: Lepidosperma prospectum and Lepidosperma sieberi. ] .
This sighting has special interest and provides an identification challenge .
Far away from home for you ? [Braidwood <–> Hyams ? ] Perhaps a NatureMapr person with home closer to Hyams can go back to this plant? With enough additional evidences you can gather a more specially interesting sighting and together we can gather an interesting identification and plant record .
No rush at all – these plants keep well in the wild ! Seeds have a bit more importance in identifying Lepidosperma spp. than these wonderful flowers in these photographs (with at least one unripe, green coloured, growing seed visible here. When ripe yellow–brown coloured.) .
Please also see some more information here in VicFlora (some more up to date, in this less out of date information, than NSW PlantNet at the moment).: https://vicflora.rbg.vic.gov.au/flora/taxon/ee5496e9-6145-4d6b-8179-afb68bcd67f5
Especially the culms width of, quotation: " ... 3–7(–10) mm wide ... " . .