Oxalis pes-caprae
Oxalis triangularis
African wood-sorrel, Bermuda buttercup, soursob
purple shamrock, scurvy grass
basal, rarely absent at flowering;
petiole 3–12 cm;
leaflets 3, green, rarely mottled with purplish red spots, angular-obcordate, (5–)7–20 mm, lobed 1/4–2/5 length, lobes apically convex, margins and abaxial surface villous, adaxial surface glabrous, oxalate deposits absent.
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.
umbelliform cymes, 2–12(–20)-flowered;
scapes often becoming fistulose proximally, 15–30 cm, sparsely villous to pilose.
umbelliform cymes, (1–)2–5(–9)-flowered;
scapes 15–35 cm, glabrous.
tristylous in diploids and tetraploids, consistently short-styled in pentaploids;
sepal apices with 2 orange tubercles;
petals deep golden yellow, 15–20 mm.
heterostylous;
sepal apices with 2 orange tubercles;
petals white to pinkish or pale purple, 15–22 mm.
not seen.
ovoid-ellipsoid, 12–18 mm, glabrous.
= 14, 28, 35.
Oxalis pes-caprae
Oxalis triangularis
Outside its native range, Oxalis pes-caprae is mostly represented by a sterile pentaploid morph, although tetraploids also are known. The occurrence of both pentaploid and tetraploid individuals in the exotic range may be the result of independent introductions (P. Michael 1964; R. Ornduff 1986). Fruit production has not been observed in North America, and the plants are assumed to be seed-sterile (Ornduff 1987). Bulbs of O. pes-caprae are rarely collected, as they detach easily from the vertical, rootlike stems. Each bulb may produce over 20, small, whitish bulblets each year. Bulblets may also be formed at the soil surface crown.
Oxalis pes-caprae was reported by J. K. Small (1933) to occur in waste places and cultivated grounds in northern Florida, but as noted by D. B. Ward (2004), no Florida specimens are known.
(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.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
LA Plants
