In order to determine whether this is Bossiaea buxifolia or Bossiaea prostrata, field notes about the colour of back of the standard (upright) petal and/or whether there is a joint between the base of the leaf and the leaf stalk or not, are needed. Buxifolia - back of the standard petal brown and the leaf stalk merging smoothly into the leaf. Prostrata- back of the standard petal pinkish red and an angled joint between the leaf and stem.
Bossiness prostrata, which this plant isn’t, has a very different habit. It grows as a lax scrambler in amongst dense grass tussocks. It’s leaves are relatively larger, more circular in outline, and well-spaced along the scrambling stems. This plant, Bossiaea buxifolua, is typically an erect or spreading subshrub, with rigid branches and tiny leaves stranded in an symmetrically alternate arrangement, closely-spaced along the stems. Box-leaved Bossiaea is an acceptable common name.
Rainer, could you have a look at the other confirmed sightings of these two species. I fear we may have got a lot of them wrong. I had always assumed that buxifolia was prostrate.