The plant gets its common name from the fact that, like the unrelated scurvy-grass, its leaves are rich in vitamin C. Sailors travelling around Cape Horn would consume the leaves to avoid scurvy. This is illustrated by this extract from the Journal of Syms Covington, who sailed aboard HMS Beagle with Charles Darwin. Here he describes the Falkland Islands, and refers to Oxalis enneaphylla as "wild thyme":
While laying here we found it very squally, and at times very cold. The island is in general mountainous. Not a single tree to be seen but there are low brushes with red berries which are very good eating. Here are bullocks horses and pigs that run wild, rabbits, wild geese and ducks and most excellent snipe shooting on the marshy ground and long grass, of which the island in general has very little else. Likewise There is the tea plant, which bears very sweet berry, and wild thyme which we used as tea, and is very good and much more plentiful than the former.