Australis covers whole Australian continent. It has specific flora dependent on long-term isolation of this continent. We can find here 19 endemic families. The amount of endemic species is more than 80 %. Australis has a developmental relationship to South America, New Zealand and Indonesia.

- ALISMA PLANTAGO-AQUATICA L. – Common Water-plantain
- ARABIS GLABRA (L.) Bernh. – Tower Mustard
- BOTRYCHIUM LUNARIA (L.) Schwartz – Common Moonwort
- CAKILE MARITIMA Scop. – Sea Rocket, Two-head Sea Rocket, European Searocket
- CALLISTEMON RIGIDUS R. Br. – Stiff Bottlebrush, Bottlebrush Tree
- CALYSTEGIA SEPIUM (L.) R. Br. – Hedge Bindweed, Bellbine
- CAREX BUXBAUMII Wahlenb. – Buxbaum’s Sedge, Club Sedge
- CUSCUTA EUROPAEA L. – European Dodder, Greater Dodder
- CYPERUS ERAGROSTIS Lam. – Drain Flat Sedge, Pale Galingale, Umbrella Sedge
- EROPHILA VERNA (L.) Bess. – Common Whitlow-grass
- GENTIANELLA MUELLERIANA (L. G. Adams) Glenny – Mueller’s Snow-gentian
- GLECHOMA HEDERACEA L. – Ground Ivy, Gill-over-the-ground
- HELIANTHUS ANNUUS L. – Common Annual Sunflower, Sunflower, Wild Sunflower
- HYOSCYAMUS NIGER L. – Henbane
- HYPERICUM PERFORATUM L. – Perforate St John´s Wort
- IPOMOEA PES-CAPRAE (L.) R. Br. – Railroad Vine, Bayhops
- IPOMOEA QUAMOCLIT L. – Cypress Vine, Cardinal Creeper, Cardinal Vine, Star Glory, Hummingbird Vine, Cypressvine Morning Glory
- LAVANDULA STOECHAS L. – French Lavender, Italian Lavender, Spanish Lavender, Topped Lavender, Wild Lavender, Bush Lavender
- MELALEUCA NESOPHILA F. Muell. – Showy Honey Myrtle
- MERREMIA UMBELLATA (L.) Hallier f. – Hogvine
- MESEMBRYANTHEMUM CRYSTALLINUM L. – Common Iceplant, Crystalline Iceplant
- PAPAVER RHOEAS L. – Common Poppy
- PROSOPIS VELUTINA Wooton – Velvet Mesquite, Native Mesquite, Arizona Mesquite
- RUMOHRA ADIANTIFORMIS (G. Forst.) Ching – Leather Fern, Leatherleaf Fern
- SESUVIUM PORTULACASTRUM (L.) L. – Seaside Purslane, Shoreline Purslane, Sea Purslane
- SWAINSONA FORMOSA (G. Don) Joy Thomps – Sturt’s Desert Pea
- TODEA BARBARA (L.) T. Moore – King Fern, Crepe Fern
- TRAPA NATANS L. – Water Chestnut
- ULEX EUROPAEUS L. – Common Gorse
- VINCA MINOR L. – Common Periwinkle, Lesser Periwinkle