Caltha obtusa; commonly known as white caltha; is a small (usually 2–6 cm), perennial herbaceous plant belonging to the family Ranunculaceae, that grows in open vegetations in mountainous areas, and is endemic to New Zealand's South Island.

The generic name Caltha has been derived from the Ancient Greek: κάλαθος (kalathos), means "goblet", and refers to the shape of the flower.

[4] The white caltha can be found in the mountains of New Zealand's South Island, from Canterbury southwards.

The spade-shaped leaves have slender petioles of 8–12 mm long that form a membranous sheathing base.

The basal lobes (or appendages) are mostly pressed against the upper surface of the leaf, are more than half as long and also have a deeply scalloped outer margin.