Flora of North America species comparison

Oxalis debilis appears to be spreading rapidly in the United States. The species produces numerous bulblets in a basal cluster and apparently also can spread laterally by production of bulblets at the tips of filiform roots or rhizomes; it can form large, dense colonies. A. Lourteig (1980) noted that plants of this species occasionally fruit but consistently reproduce through abundant bulblets. They apparently are seed-sterile in North America.

Oxalis corymbosa and O. debilis were differentiated by A. Lourteig (2000) primarily by the distribution of oxalate deposits in the leaf lamina. In O. debilis, the dotlike deposits are crowded along the margins and absent to distinctly less abundant elsewhere. In O. corymbosa, the deposits are evenly distributed over the whole lamina. In their native range in South America, the two expressions are broadly sympatric and intermediates are common, as they are in the flora area. Intermediates have the oxalate dots along the margins as well as over the whole surface or sometimes mostly on the outer third of the blades, near the margins. There is no justification for formal recognition of two entities.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Genera 5, species ca. 800 (1 genus, 36 species in the flora).

Oxalidaceae occurs mostly in the tropics and subtropics of both hemispheres but extends into temperate regions. Species of Averrhoa Linnaeus and Sarcotheca Blume are trees or shrubs, those of Dapania Korthals lianas; all have fleshy, baccate fruits. Species of Biophytum de Candolle and Oxalis are herbs, subshrubs, shrubs, or rarely vines with capsular fruits; Biophytum has even-pinnate leaves fascicled at the stem tips. Seeds of Oxalidaceae develop an elastic, translucent, arilliform epidermis that turns inside out, explosively ejecting them from the capsule (K. R. Robertson 1975).

Oxalis tuberosa Molina (oca or New Zealand yam), of Andean South America, is cultivated for its edible tubers. Averrhoa is widely cultivated in the tropics for its fruits, which are eaten fresh, used in drinks, or made into jelly and jam. Both species of Averrhoa [A. bilimbi Linnaeus (bilimbi or cucumber tree), A. carambola Linnaeus (starfruit or carambola)] are known only in cultivation or as escapes from cultivation.

(Discussion copyrighted by Flora of North America; reprinted with permission.)