California wood-sorrel California wood-sorrel

Xanthoxalis californica Abrams, Bull. Torrey Bot. Club 34: 264. 1907; Oxalis albicans Kunth subsp. californica (Abrams) G. Eiten

Herbs perennial, caulescent, rhizomes and stolons absent, bulbs absent. Aerial stems usually 2–8 from base, erect to ascending, 10–40 cm, becoming woody proximally, glabrous or very sparsely short-puberulent, <hairs curved-ascending, nonseptate>. Leaves basal and cauline; stipules oblong, margins narrowly flanged, apical auricles absent; petiole 3–8 cm, <hairs nonseptate>; leaflets 3, gray-green, obcordate, 8–15 mm, lobed 1/5–1/3 length, surfaces sparsely strigose, oxalate deposits absent. Inflorescences umbelliform cymes, 1(–3)-flowered; peduncles 2–9 cm. Flowers distylous; sepal apices without tubercles, <surfaces glabrous>; petals yellow, with red lines proximally, 7–11(–13) mm. Capsules angular-cylindric, abruptly tapering to apex, 10–15 mm, strigillose, <hairs very short, nonseptate>.

Flowering (Dec–)Feb–Apr(–Jun). Slopes and flats, brushy ridges, roadside banks, canyon bottoms, rock outcrops, grasslands, oak chaparral, coastal sage scrub; (0–)30–800 m; Ariz., Calif.; Mexico (Baja California).

Oxalis californica is recognized by its caulescent habit, stems with reduced vestiture (glabrous or very sparsely short-puberulent), one (to three) flowers on long peduncles and pedicels, the yellow corollas often drying with a blue or purplish tinge, and relatively wide, glabrous, and usually purplish or pinkish tinged sepals.