Oxalis debilis
Oxalis triangularis
pink wood-sorrel, world-wide wood-sorrel
purple shamrock, scurvy grass
basal;
petiole 10–25 cm;
leaflets 3, green to yellowish green, rounded-obcordate, 17–40(–50) mm, lobed 1/6–1/5 length, lobes apically convex, adaxial surface hirsute, adaxial surface glabrous, oxalate deposits in dots at least around distal margins, often evenly over surface.
basal, rarely absent at flowering;
petiole 12–20 cm;
leaflets 3, dark purple, commonly with lighter violet splotches radiating from midvein adaxially, obtriangular to obovate-triangular, (20–)30–50(–60) mm, lobed 1/10 length or apex merely notched, lobes apically truncate to slightly convex, surfaces glabrous, oxalate deposits absent or in short, marginal lines on both sides of notch.
irregular cymes, (3–)8–14(–28)-flowered;
scapes 15–28 cm, moderately villous to glabrate.
umbelliform cymes, (1–)2–5(–9)-flowered;
scapes 15–35 cm, glabrous.
mostly homostylous, infrequently tristylous;
sepal apices with 2 orange tubercles;
petals violet to lavender or rose purple, 10–16(–20) mm.
heterostylous;
sepal apices with 2 orange tubercles;
petals white to pinkish or pale purple, 15–22 mm.
not observed.
ovoid-ellipsoid, 12–18 mm, glabrous.
= 14, 28, rarely 35.
Oxalis debilis
Oxalis triangularis
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.)
In East Feliciana Parish, Louisiana, north of Baton Rouge, Oxalis triangularis has spread from a planter pot into adjacent woods (G. F. Guala, pers. comm.). In Leon County, Florida, a population is growing and slowly spreading at the edge of a woodland remnant within the city of Tallahassee (L. C. Anderson, pers. comm.).
A. Lourteig (2000) recognized two subspecies sympatric over much of their native ranges (as cited, subsp. triangularis in Argentina, Bolivia, Brazil, and Paraguay, subsp. papilionacea in Bolivia, Brazil, Paraguay, and Peru) and differing by the following contrasts: subsp. triangularis has sepals acute, oxalate tubercles small or absent, and petals white to purplish, three to four times longer than the sepals; subsp. papilionacea has sepals obtuse to subacute with oxalate tubercles thickened, and petals pink to purplish, rarely white, about two to two and a half times longer than the sepals. With these subtle differences and broad sympatry, it seems probable that only a single evolutionary entity exists. In any case, the few North American collections studied here would be Oxalis triangularis in the strict sense. Forms of O. triangularis are sometimes recognized as “atropurpurea” but apparently this is a horticultural name.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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Flora NW
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PNW Herbaria
WildflowerSearch
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