Oxalidaceae

Woodsorrel Family

Woodsorrels

FAMILY: Woodsorrel family (Oxalidaceae) – Oxalis genus.

SPECIES: #1 creeping woodsorrel (Oxalis corniculata L. = Oxalis repens Thunb. = Oxalis villosa M. Bieb.). #2 slender yellow woodsorrel (Oxalis dillenii Jacq. = Oxalis filipes Small = Oxalis florida Salisb. = Oxalis prostrata Haw.). #3 common yellow woodsorrel (Oxalis stricta L. = Oxalis europaea Jord. = Oxalis fontana Bunge). #4 purple woodsorrel (Oxalis violacea L.).

TO UTILIZE AS FOOD: Warning! Woodsorrels are high in oxalic acid and should only be eaten in moderation. All species listed above have edible leaves, flowers, and young fruits. In addition, purple woodsorrel (O. violacea) and a few species native to Mexico are reported to have edible roots.

Woodsorrels have distinctive leaves, each with 3 (or more in a few species) heart-shaped leaflets elevated on a long stalk. Based on the species noted below, leaves of any age are suitable for gathering. They don’t become tough or bitter with age. Fresh leaves taste pleasantly tangy, as if marinated in vinaigrette dressing. They’re perfect for salads. No harsh accents compromise the agreeable flavor. Note that oxalic acid, which is harmful in large amounts, is responsible for imparting the tangy flavor. All the aboveground parts can be tossed into soups or salads. Woodsorrel leaves have a delicate texture. Even the stalks are delicate, at least when young. Older stalks become stringy. Developing fruits still in the green stage are moist and tender. Older fruits dry out and split open to release a number of seeds. None of the references cited in the bibliography indicate that the seeds are edible, so consumption of the seeds is not recommended. Woodsorrels are low-growing, colony-forming plants found throughout the United States. In the Southwest, they grow over a wide range of elevations in canyons, meadows, disturbed areas, forests, and other habitats that aren’t too dry. They can be gathered throughout much of the growing season.

NOTES: Species sampled for this reference include: creeping woodsorrel (O. corniculata), common woodsorrel (O. stricta), and one of the purple-flowered species, presumably alpine woodsorrel (O. alpina = O. metcalfei = O. monticola), which is really no different than purple woodsorrel (O. violacea) or any other purple-flowered species. Call it what you wish as the identification keys and scientific names follow no sensible order in this genus and change every time a book is published. At least recognizing the genus is easy thanks to the trifoliate leaves with obcordate leaflets of most species. This feature in combination with the flowers and overall form is a sure sign. Finding woodsorrels is also easy. They’re very common in the Southwest and elsewhere.

IDENTIFICATION: About 25 species of the Oxalis genus are found in the United States. Only 5-10 species occur in the Southwest and Great Basin. The scientific names in this genus are a mess and will probably change in the future.

Description of woodsorrels (the Oxalis genus): FORM low-growing perennial plants emerging from bulbs, rhizomes, or taproots; stems absent or short; LEAVES compound, alternate, palmate, and stalked; leaflets 3-7 (usually 3), generally obcordate, folded along the midveins, and notched at the tips; FLOWERS regular, perfect, ovary superior, and arranged individually or a few in cymes; sepals 5, free, and green; petals 5, free, white, yellow, pink, purple, or blue; pistils 1, consisting of 5 united carpels; styles 5, free; stamens 10, united at the bases, and of 2 different lengths: 5 long and 5 short; FRUITS capsules narrowly cylindrical, 5-celled, and splitting open explosively; HABITAT fields, canyons, meadows, and mountain streams; nearly throughout the Southwest and elsewhere; blooming in spring and summer.

REFERENCES: Couplan (pp. 313-314) indicates that the leaves, flowers, and immature fruits of the following species are edible: #1 creeping woodsorrel (Oxalis corniculata = O. repens = O. villosa), #2 slender yellow woodsorrel (Oxalis dillenii = O. filipes = O. florida = O. prostrata), #3 common yellow woodsorrel (Oxalis stricta = O. europaea = O. fontana), and #4 purple woodsorrel (Oxalis violacea). In addition, Castetter (1936 p. 47) indicates that the bulbs of Oxalis violacea (purple woodsorrel) are edible.