Oxalis pes-caprae
Oxalis macrantha
African wood-sorrel, Bermuda buttercup, soursob
Price's wood-sorrel
usually 2–8 from base, erect initially, usually becoming decumbent, 5–20(–40) cm, becoming woody proximally, hirsute-pilose on at least proximal 2/3, hairs curved, loosely and irregularly spreading, nonseptate.
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 and cauline;
stipules oblong, margins narrowly flanged or without free portions, apical auricles absent;
petiole 2–7 cm;
leaflets 3, green, obcordate, 3.5–12 mm, lobed 1/5–1/3 length, surfaces usually strigose-hirsute, sometimes glabrate, oxalate deposits absent.
umbelliform cymes, 2–12(–20)-flowered;
scapes often becoming fistulose proximally, 15–30 cm, sparsely villous to pilose.
umbelliform cymes, less commonly irregular cymes, (1–)3–8-flowered;
peduncles (3–)5–10(–15) cm.
villous, hairs long, spreading.
tristylous in diploids and tetraploids, consistently short-styled in pentaploids;
sepal apices with 2 orange tubercles;
petals deep golden yellow, 15–20 mm.
distylous, well above level of leaves;
sepal apices without tubercles;
petals yellow to yellow-orange, with prominent red lines proximally, (13–)15–20(–23) mm.
not seen.
angular-cylindric, abruptly tapering to apex, 10–15 mm, sparsely to densely hirsute-pilose, hairs long, sometimes mostly along angles.
brown, transverse ridges usually white.
= 14, 28, 35.
Oxalis pes-caprae
Oxalis macrantha
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.)
Oxalis macrantha is restricted mostly to limestone glades in Alabama, Kentucky, and Tennessee. It is recognized by its villous to villous-hirsute stems, flowers in umbelliform cymes, and large yellow to yellow-orange corollas with red lines proximally. The lines in the throat remain visible after drying and usually can be seen on herbarium specimens even from the outside of the flower. A similar pattern also occurs in other species, especially O. grandis, O. illinoensis, and O. texana.
Seemingly disjunct plants of native habitats in Nuevo León, Mexico, identified as Oxalis macrantha apparently are more common than reported by G. L. Nesom (2009b). Whether these are actually disjunct or a parallel morphological expression derived from some Mexican species needs to be investigated.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
