Swainsona novae-zelandiae is small, rare, alpine member of the pea family, 2–4 in (5–10 cm) high. It is inconspicuous as the grey foliage closely matches the surrounding rocks. The leaves have 6–10 pairs of small oval leaflets. The flowers are a pale pink-purple.
Swainsona novae-zelandiae is found in drier subalpine to low-alpine areas of the South Island of New Zealand, from Marlborough to north Otago.