Geranium sessiliflorum is an herbaceous clump-forming perennial. The round leaves are 0.4–0.8 in (10–20 mm) and maybe green or bronze. White flowers in summer.
Geranium sessiliflorum is found in screes, short grassland and herbfields, in montane areas of North Island, South Island and Stewart Island, New Zealand. It is also found in Australia, Tasmania and Chile.