Oxalis dillenii
Oxalis colorea
common yellow wood-sorrel, Dillen's oxalis, graygreen sorrel, slender yellow wood-sorrel, southern yellow wood-sorrel
Small's wood-sorrel
(1–)2–8 from base, erect initially, often becoming decumbent or prostrate and stolonlike, rarely rooting at nodes, 10–25 cm, usually herbaceous, sometimes becoming woody proximally, densely and evenly strigillose to strigose from base to peduncles and pedicels, hairs straight, antrorsely appressed, nonseptate, sharp-pointed.
usually 1–4 from base, mostly erect, 5–15(–25) cm, often becoming woody proximally, hirsute-pilose proximally, hairs curved, irregularly spreading or slightly deflexed, sometimes ± antrorse on peduncles and pedicels, nonseptate.
basal and cauline;
stipules oblong, margins narrowly flanged or without free portions, apical auricles absent;
petiole 1–4 cm, hairs nonseptate;
leaflets 3, green, obcordate, (4–)6–15(–21) mm, lobed 1/5–1/3 length, abaxial surface sparsely strigillose, 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, 3–8 mm, lobed 1/5–1/3 length, surfaces usually sparsely strigose-hirsute, sometimes glabrate, oxalate deposits absent.
usually umbelliform cymes, rarely irregular cymes, 1–3(–8)-flowered;
peduncles 1–6(–10) cm.
usually umbelliform cymes, sometimes irregular cymes, (1–)2–4(–5)-flowered;
peduncles (3–)5–10(–15) cm.
strigose, hairs short, curved antrorsely.
mostly homostylous;
sepal apices without tubercles;
petals yellow, without red lines, (2.5–)4–8 mm.
tristylous, well above level of leaves;
sepals 3.5–5 mm, apices without tubercles;
petals yellow to orange-yellow, usually with prominent, rarely faint, red lines proximally, very rarely lines absent, 9–15 mm.
angular-cylindric, abruptly tapering to apex, 12–20(–25) mm, densely strigose-pilose, hairs both appressed and spreading, with puberulent understory.
angular-cylindric, abruptly tapering to apex, 6–16 mm, glabrate to puberulent or sparsely hirsute-strigose, hairs short, sometimes only along angles or at apex.
brown, transverse ridges with strong grayish or white lines.
brown, transverse ridges usually white.
= 18, 20, 22, 24.
Oxalis dillenii
Oxalis colorea
Decumbent stems of Oxalis dillenii often appear stolonlike, producing erect branches and leaves at the nodes, rarely producing a few adventitious roots. Such plants sometimes are misidentified as O. corniculata, but they differ in their overall habit, stems and rhizomes that become woody, reduced stipules, strigillose cauline vestiture, denser fruit vestiture, and seed color. Plants of O. dillenii in Canada and the western United States appear to be adventive.
Plants of Oxalis dillenii flowering into November and December in Texas and North Carolina, and probably elsewhere, characteristically are depressed in habit, with creeping stems and forming matlike colonies. The corollas are small, with petals 2.5–3 mm. Although similar in habit to typical O. corniculata, these plants do not have stems that root at nodes, and the strigillose vestiture, though reduced in density, and the stipule morphology are like O. dillenii. Whether these are the same genotype as spring-flowering plants or a different entity remains to be investigated. At least some of the variability in O. dillenii, particularly in habit, may be genetically partitioned, as dysploid chromosome races apparently exist.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Oxalis colorea is common in southeastern Alabama, Mississippi, and probably the northern half of Georgia; outliers apparently occur in a wider area toward the north and northeast. Scattered variants from widely scattered localities in Alabama, Mississippi, and Tennessee, from within the geographic range of O. colorea, have the habit and prominently red-lined petals of O. colorea; stem hairs are relatively long but are antrorsely oriented, as in O. florida.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
OR, 
WA - Local Web sites:
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria, 
SW CO Wildflowers 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
