# Redwood Sorrel (*oxalis smalliana*) Redwood Sorrel (Oxalis smalliana), also known as Small's woodsorrel, is an elegant perennial herb that flourishes on the damp, shaded floors of temperate forests. Famous for its delicate clover-like leaves, this plant forms lush, velvety carpets under dense forest canopies where direct sunlight rarely penetrates. It has evolved a highly sensitive nature: when exposed to intense light or dry conditions, its leaflets fold neatly downward to conserve precious moisture and protect its photosynthetic machinery, only to reopen when gentle shade returns. During the spring and summer months, it produces small, pristine white to light pink five-petaled blossoms that stand out brilliantly against the dark forest floor. This resilient understory species plays a critical role in stabilizing forest soils and maintaining understory humidity, making it a key component of its native woodland ecosystems. - **Category:** [Plants](https://www.snappit.app/explore/categories/plant) - **Rarity:** Common - **Danger:** 1/5 · Very low - **Snaps:** 5 - **Habitat:** Typically found in moist, deeply shaded temperate woodlands and mountain valleys, thriving on humus-rich soils near forest streams. ![Redwood Sorrel](https://inaturalist-open-data.s3.amazonaws.com/photos/294594629/medium.jpeg) Photo: Ed Alverson, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/294594629) ## Appearance Redwood Sorrel features clusters of three heart-shaped leaflets, each about 1 to 3 centimeters wide, connected to delicate, reddish-green petioles rising directly from underground rhizomes. The leaves are a vibrant emerald green on top, sometimes showing a lighter chevron pattern, while their undersides can carry a subtle purplish tint. Its solitary, cup-shaped flowers measure roughly 1.5 to 2 centimeters across and consist of five overlapping petals. These petals are white to pale lavender-pink, decorated with fine, darker pink veins that converge toward a bright yellow center. ## Taxonomy - **Kingdom:** Plantae - **Phylum:** Tracheophyta - **Class:** Magnoliopsida - **Order:** Oxalidales - **Family:** Oxalidaceae - **Genus:** Oxalis ## Interesting facts - It spreads effectively through underground rhizomes, allowing a single plant to form vast, interconnected clonal colonies over time. - Its rapid leaf-folding reaction is a form of rapid plant movement, triggered by changes in turgor pressure within specialized cell joints called pulvini. - The plant contains oxalic acid, which gives its leaves a tart, green-apple flavor often compared to sorrel, though consuming large amounts can be toxic. ## Special abilities - **Nyctinastic Folding:** The leaves fold downward along their center vein during intense sunlight or at night to minimize water loss and protect delicate leaf tissue. - **Extreme Shade Tolerance:** It can efficiently carry out photosynthesis in low-light environments, utilizing less than one percent of direct sunlight. - **Oxalic Acid Protection:** Accumulates high concentrations of oxalic acid in its cells, giving the plant a sour taste that deters many generalist herbivores. ## Measurements & details - **Length:** 5-15 cm - **Lifespan:** 3-8 years ## Diet & Feeding As a photoautotroph, it produces its own energy by capturing sunlight and converting carbon dioxide and water into sugars. - **Primary Foods:** Sunlight, Water, Carbon dioxide, Soil nitrogen ## Ecological connections - **Mutualism:** Japanese Cedar (*Cryptomeria japonica*) — Provides the dense canopy shade and acidic leaf litter necessary for the sorrel to thrive. - **Eaten by:** [Sika Deer](https://www.snappit.app/explore/sika-deer) (*Cervus nippon*) — Occasionally grazes on the leaves as a minor part of its herbaceous diet. - **Mutualism:** Asian Honey Bee (*Apis cerana*) — Visits the spring blossoms to collect nectar, acting as a primary pollinator. ## Safety **Danger:** 1/5 · Very low No special safety notes yet. ## Frequently Asked Questions ### How to identify Redwood Sorrel? Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details. ### How long is Redwood Sorrel? 5-15 cm ### How long does Redwood Sorrel live? 3-8 years ### What does Redwood Sorrel eat? As a photoautotroph, it produces its own energy by capturing sunlight and converting carbon dioxide and water into sugars. ### Where is Redwood Sorrel usually found? Typically found in moist, deeply shaded temperate woodlands and mountain valleys, thriving on humus-rich soils near forest streams. ## Where to spot - [Armstrong Redwoods State Natural Reserve](https://www.snappit.app/guides/places/armstrong-redwoods-state-natural-reserve) — California, US · State Park - [Benbow Lake State Recreation Area](https://www.snappit.app/guides/places/benbow-lake-state-recreation-area) — California, US · State Park - [Mendocino and Headlands Historic District](https://www.snappit.app/guides/places/mendocino-and-headlands-historic-district) — US · Historic District [View all places to see Redwood Sorrel](https://www.snappit.app/guides/where-to-see/redwood-sorrel) ## More Plants - [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*) - [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*) - [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*) - [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*) --- Source: [Redwood Sorrel: Facts & Places to See — Snappit](https://www.snappit.app/explore/redwood-sorrel)