Oxalis articulata
Oxalis triangularis
pink oxalis, pink sorrell, windowbox wood-sorrel
purple shamrock, scurvy grass
basal;
petiole 11–30 cm;
leaflets 3, green to purplish abaxially, green adaxially, rounded-obcordate, 18–20 mm, margins densely loosely ciliate, lobed 1/5–1/3 length, lobes apically convex, surfaces evenly strigose-villous to strigose-hirsute, oxalate deposits in dots concentrated mostly toward margins or over whole 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.
usually umbelliform cymes, less commonly in irregular cymes, 3–12-flowered;
scapes 12–28 cm, sparsely strigose.
umbelliform cymes, (1–)2–5(–9)-flowered;
scapes 15–35 cm, glabrous.
heterostylous;
sepal apices with 2 orange tubercles;
petals usually purplish rose to red, rarely white, 10–14 mm.
heterostylous;
sepal apices with 2 orange tubercles;
petals white to pinkish or pale purple, 15–22 mm.
ovoid, 4–8 mm, sparsely strigose.
ovoid-ellipsoid, 12–18 mm, glabrous.
= 42.
Oxalis articulata
Oxalis triangularis
Oxalis articulata in the United States commonly has been identified as O. rubra. Oxalis rubra was treated at subspecific rank by A. Lourteig (1982), but subsp. articulata and subsp. rubra have essentially the same native range and occur in similar habitats. Lourteig identified both subspecies in the United States, noting in her key that vestiture is reduced and the sepals are broader in subsp. rubra. Evidence is weak for recognizing more than a single entity. In the Flora of Panama (Lourteig 1980), she recognized only O. articulata, noting that it is naturalized in other parts of America and in the Old World.
(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.)
OR
CalFlora
Flora NW
LA Plants
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
