Notothlaspi australe is a species of alpine Brassicaceae from New Zealand. These species are often called penwipers, which can apply as a generic term for this species as well. It is endemic to the South Island of New Zealand.
Description.
"Notothlaspi australe" is a small plant, with radiating leaves from a central stem. The leaves have a small pointed tip, and are green to brown. They are "3.0–6.5 mm wide, ovate to broadly ovate and with 1–6 teeth". The form is prostrate. 
The flowers are small and white, with a single flower forming from the axil of the uppermost stem. Young plants may form a single rosette, but with time these will branch out to form multiple, matted rosettes.
"Notothlaspi australe" is perennial, unlike "Notothlaspi rosulatum".
Distribution and habitat.
"Notothlaspi australe" is known exclusively on to the northern mountain ranges of the South Island of New Zealand, where it is present in alpine and subalpine habitats. "Notothlaspi australe" does not tend to live on the subranges that are composed of ultramafic rock like Maungakura / Red Hill, where the newly described "Notothlaspi viretum" dominates instead.
Ecology.
"Notothlaspi australe" is one of the few species that lives in plant communities on barren alpine rock and scree fields, along with plants like "Anistome imbricata", "Dracophyllum pronum", "Veronica pulvinaris", and grasses like "Poa colensoi".
Taxonomy and etymology.
"Notothlaspi australe" contains the following varieties:
The type specimen is from Gordon's Knob, in Nelson, New Zealand. The species name "australe" comes from the Latin adjective "australis", and means 'southern'.
Conservation.
"Notothlaspi australe" is considered Not Threatened, but it has two qualifiers attached, DPS and DPT, both of which indicate that more data is needed for this species.