This species grows in cool, moist Douglas-fir and coastal redwood forests in the Cascade, Olympic, and Coast Mountains from southwest British Columbia to the San Francisco Bay area of California. Being adapted to shady environments, redwood sorrel is capable of photosynthesis at low light levels. Higher intensity light can damage the sensitive leaves. As a protective measure, leaves fold downward within several minutes when struck by direct light, a process known as nyctinasty.
PLANTS Profile – Oxalis oregana, redwood sorrel
Kingdom Plantae – Plants
Subkingdom Tracheobionta – Vascular plants
Superdivision Spermatophyta – Seed plants
Division Magnoliophyta – Flowering plants
Class Magnoliopsida – Dicotyledons
Subclass Rosidae
Order Geraniales
Family Oxalidaceae – Wood-Sorrel family
Genus Oxalis L. – woodsorrel
Species Oxalis oregana Nutt. – redwood-sorrel
Bay Area Naturalist: Redwood Sorrel
Places to See Redwood Sorrel: Henry Cowell Redwoods State Park
Plant of the Week: Redwood Sorrel (Oxalis oregana)
Plant Profile: Redwood Sorrel (Oxalis oregana)
Plant Itineraries 