[1][2] This genus is endemic to coastal eastern New South Wales in Australia.

[3] This genus was named in honour of the species discoverer, Australian botanist Alexander Floyd (1926-2022).

[4][5] Alexfloydia repens is a spreading, mat-forming grass found on the margins of brackish and tidal waterways in areas flooded by unusually high tides (called "king tides").

[6] The species forms a groundcover associated with the tree species Casuarina glauca and the Endangered Ecological Community Swamp Oak Floodplain Forest.

[7] Alexfloydia repens is the sole larval food plant for the endangered Black grass-dart butterfly (Ocybadistes knightorum) (Lambkin & Donaldson, 1994).