Oxalis oregana, known as redwood sorrel or Oregon oxalis, is a species of the wood sorrel family, Oxalidaceae, in the genus Oxalis native to moist Douglas-fir and coast redwood forests of western North America from southwestern British Columbia to Washington, Oregon, and California.[1] [2]
Oxalis oregana is a short, herbaceous perennial with erect flowering stems 5–15 cm tall. The three leaflets are heart-shaped, 1–4.5 cm long with purplish undersides, on 5–20 cm stalks. The inflorescence is 2.4–4 cm in diameter, white to pink with five petals and sepals. The hairy five-chambered seed capsules are egg-shaped, 7–9 mm long; seeds are almond-shaped.[3] It spreads by a scaly rhizome varying the size of patches. They can be seen throughout moist forest under-canopies.[4]
Oxalis oregana photosynthesizes at relatively low levels of ambient sunlight (1/200th of full sunlight). When direct sunlight strikes the leaves they fold downwards; when shade returns, the leaves reopen. Taking only a few minutes, this movement is observable to the eye.[5] [6]
The leaves of Oxalis oregana are eaten by the Cowlitz, Quileute and Quinault peoples. Like spinach, they contain mildly toxic oxalic acid, which is named after the genus.[7] They are safe to eat in small amounts for those with no oxalate-related conditions.[8]