Weymouthia occurs in southern South America, New Zealand and south-eastern Australia and Lord Howe Island.

It is characterised by (i) its monopodial, often hanging growth form; (ii) slight differences between stem and branch leaves; and (iii) the straight perichaetial leaves.

[1] Weymouthia was named in honour of William Anderson Weymouth (1842–1932), a prominent Tasmanian botanist.

The species epithet cochlearifolia refers to the spoon-shaped leaves that resemble those of scurvy-grass.

Later the genus was included in the Lembophyllaceae,[1] but according to recent cladistic analyses based on DNA, this family is polyphyletic, and its revision is to be expected.