Walking along the beach east of Port Fairy, local volunteers John and Joan Young saw a funny looking grass. There was some lovely silvery Hairy Spinifex (Spinifex sericeus), but right beside it was something that looked a bit different. A bit of googling, some emails, and then confirmation by native grass expert, Dr Graeme Lorimer, that the sneaky greenish grass was the invasive Sea Wheat-grass (Thinopyrum junceiforme).
Sea Wheat-grass has been planted as a sand-stabiliser elsewhere, but it has also been mistaken for Hairy Spinifex and mistakenly planted in revegetation works. This patch is in an area of coast which has very few records (see map below), so there are still hopes of controlling it.
Moral of the story? Check your grass identifications, twice, especially if you are doing revegetation.