Oxalis pilosa

Nuttall in J. Torrey and A. Gray

Fl. N. Amer. 1: 212. 1838.

Common names: Hairy western wood-sorrel
Synonyms: Oxalis albicans subsp. pilosa (Nuttall) G. Eiten O. corniculata subsp. pilosa (Nuttall) Lourteig O. corniculata var. pilosa (Nuttall) B. L. Turner O. wrightii var. pilosa (Nuttall) Wiegand Xanthoxalis pilosa (Nuttall) Small
Treatment appears in FNA Volume 12. Treatment on page 143. Mentioned on page 137.

Herbs perennial, caulescent, rhizomes and stolons absent, bulbs absent. Aerial stems usually 2–8 from base, decumbent to ascending, 10–40 cm, becoming woody proximally, sparsely to densely pilose, hairs spreading irregularly to ± deflexed, nonseptate, longer hairs 0.6–1.2 mm. Leaves basal and cauline; stipules oblong, margins narrowly flanged, apical auricles absent; petiole (1–) 2–6 cm, hairs nonseptate; leaflets 3, glaucous and gray-green to yellowish green, obcordate, 5–12 mm, lobed 1/5–1/3 length, surfaces glabrous to loosely strigose to hirsute-villous, oxalate deposits absent. Inflorescences umbelliform cymes, 1–2 (–3) -flowered; peduncles 1.5–5 cm. Flowers semihomostylous or distylous, within level of leaves; sepal apices without tubercles, surfaces strigose to hirsute-strigose; petals yellow, rarely with red lines proximally, 8–12 mm. Capsules angular-cylindric, abruptly tapering to apex, 12–17 (–20) mm, strigose-hirsute. Seeds brown to blackish brown, transverse ridges rarely with whitish lines or spots.


Phenology: Flowering (Feb–)Mar–Jun(–Oct).
Habitat: Juniper-grasslands, pinyon-juniper, oak-juniper, oak, oak-pine, rocky and grassy hillsides, riparian woods (sycamore-walnut, cottonwood-willow), canyons, stream banks, washes, gravel bars.
Elevation: (700–)900–1900(–2000) m.

Distribution

V12 10-distribution-map.jpg

Ariz., Calif., Nev., N.Mex., Oreg., Utah, Mexico (Baja California), Mexico (Chihuahua), Mexico (Coahuila), Mexico (Durango), Mexico (Nuevo León), Mexico (Sonora)

Discussion

Oxalis pilosa has been treated as an infraspecific entity within O. albicans, but the two are sympatric in the southwestern United States and although each is variable, there appear to be relatively few unequivocal intermediates. Reports of O. pilosa from Texas apparently were based on misidentifications of O. albicans and perhaps also of O. dillenii.

Selected References

None.

Lower Taxa

None.

"alternating" is not a number."/5" is not declared as a valid unit of measurement for this property.

... more about "Oxalis pilosa"
5 cm50 mm <br />0.05 m <br /> (?) +
Guy L. Nesom +
Nuttall in J. Torrey and A. Gray +
subpalmate +  and pinnate +
1.7 cm17 mm <br />0.017 m <br /> (2 cm20 mm <br />0.02 m <br />) +
strigose-hirsute +
tapering +  and angular-cylindric +
1.2 cm12 mm <br />0.012 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
taprooted +  and fibrous-rooted +
Hairy western wood-sorrel +
umbelliform +
Ariz. +, Calif. +, Nev. +, N.Mex. +, Oreg. +, Utah +, Mexico (Baja California) +, Mexico (Chihuahua) +, Mexico (Coahuila) +, Mexico (Durango) +, Mexico (Nuevo León) +  and Mexico (Sonora) +
(700–)900–1900(–2000) m. +
Juniper-grasslands, pinyon-juniper, oak-juniper, oak, oak-pine, rocky and grassy hillsides, riparian woods (sycamore-walnut, cottonwood-willow), canyons, stream banks, washes, gravel bars. +
axillary +  and terminal +
whorled +  and alternate +
cauline +  and basal +
gray-green;yellowish green +
lobed +  and obcordate +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
whitish +  and red +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
orange +  and black +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 m <br />) +
connate +  and distinct +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
Flowering (Feb–)Mar–Jun(–Oct). +
Fl. N. Amer. +
connate +  and distinct +
free +  and connate +
creeping +  and prostrate +
decumbent;ascending +
10 cm100 mm <br />0.1 m <br /> (40 cm400 mm <br />0.4 m <br />) +
distinct +
strigose;hirsute-strigose +
Oxalis albicans subsp. pilosa +, O. corniculata subsp. pilosa +, O. corniculata var. pilosa +, O. wrightii var. pilosa +  and Xanthoxalis pilosa +
Oxalis pilosa +
species +