Slender Yellow Woodsorrel

Flowers are a nectar source for the Falcate Orangetip butterfly (Anthocharis midea).

Xanthoxalis rufa Small, Fl. SE. U. S. 668. 1903
Oxalis /nr'a Small, in Britton, Man. 577. 1901.
Stems erect and 1.5—1 dm. tall, or sometimes diffusely branched and with some of the branches decumbent, loosely pubescent, usually sparingly so, or almost glabrous, the rootstocks slender and often elongate ; leaflets reddish or purplish, but often fading to green, the blades S-20 mm. wide, sparingly strigillose or glabrous especially in age, except the ciliate margins ; peduncles much longer than the petioles ; pedicels conspicuously short, the several flowers, or capsules, clustered ; sepals 3-4 mm. long; petals rather bright-yell' iw, 7-10 mm. long; filaments glabrous; capsules short-columnar, 7-9 mm. long, glabrous, abruptly pointed at the apex.
Type locality : Xew York Botanical Garden, cultivated ; from Monroe County, Pennsylvania.
Distribution : Massachusetts to Minnesota and Georgia.

Xanthoxalis cymosa Small, Fl. SE. U. S. 668. 1903
Oxalis cymosa Small, Bull. Torrev Club 23 : 267. 1896.
Oxalis corniculata B. L. Robinson, Jour. Bot. 44: 390. 1906. Not O. corniculata L,. 1753.
Stems erect, 2-11 dm. tall, loosely pubescent or nearly glabrous, arising from slender rootstocks ; leaflets bright-green or deep-green, the blades 10-27 mm. broad, glabrous or with scattered hairs on both surfaces and ciliate ; peduncles much longer than the petioles ; pedicels villous, not refracted in fruit ; sepals 3-1 mm. long at maturity ; petals deepyellow, 7-10 mm. long ; longer filaments glabrous ; capsules columnar, slender, 10-16 mm. long, very sparingly pubescent, gradually narrowed at the apex.
Type locality' : Riverdale, New York.
Distribution : Ontario to Michigan, Florida. Nebraska, and Texas.

Xanthoxalis texana Small, Fl. SE. U. S. 667. 1903
Stems erect or slightly decumbent, but not elongate as in A", stricta, and densely strigillose, but with the hairs less appressed than in the case of that species, the horizontal rootstocks elongate; leaflets bright-green, the blades mostly 10-13 mm. wide, strigillose; peduncles conspicuously elongate and much overtopping the stem or its branches ; pedicels strigillose, conspicuously elongate; sepals 5.5-6.5 mm. long at maturity; petals golden-yellow, 12-18 mm. long; filaments glabrous, more or less dilated, the inner ones often conspicuously so ; capsules columnar, 12-15 mm. long.
Typk locality : Alvin, Texas. Distribution : Texas.

Xanthoxalis brittoniae Small, Fl. SE. U. S. 668. 1903
Oxalis Brittoniae Small, in Britton, Man. 577. 1901.
Stems erect or spreading, 1-4 dm. tall, mostly rather fleshy, loosely pubescent, often finely hirsute below, but commonly sparsely pubescent in age, the hairs more appressed above ; leaflets bright-green, the blades mostly 10-16 mm. broad, commonly slightly strigillose and ciliate ; peduncles longer than the petioles ; pedicels strigillose, not refracted at maturity; sepals 3-4 mm. long; petals light-yellow, 5-10 mm. long; longer filaments pubescent; capsules rather slender, 8-12 mm. long, minutely and sparingly pubescent, gradually tapering at the apex.
Type locality : Staten Island, New York.
Distribution : Massachusetts to Missouri and Florida.

Xanthoxalis filipes Small, Fl. SE. U. S. 667. 1903
Oxalis fil, pes Small ; Britt. & Brown, 111. Fl. 2 : 349. 1897.
Steins erect, or decumbent at the base, 1-3 dm. tall, usually very slender and wiry, finely pubescent, often sparingly so, and with the hairs more appressed on the upper parts than on the lower; leaflets bright-green, the blades 4-8 mm. broad or sometimes slightly wider, minutely strigillose, or glabrous in age ; peduncles as long as the petioles or longer ; pedicels strigillose, refracted at maturity ; sepals 3-4 mm. long ; petals lightor pale-yellow, 5-9 mm. long; longer filaments pubescent ; capsules slender, 8-13 mm. long, minutely but closely pubescent, more abruptly narrowed at the apex than those of X. Brittoniae .
Tpe locality : Falls of the Yadkin River, Stanley County, North Carolina.
Distribution : District of Columbia to Missouri and Georgia.

Xanthoxalis bushii Small, Fl. SE. U. S. 667. 1903
Oa alis Bushii Small, Bull. Torrev Club 25 : 611. 1S98.
<> alis coloradensis Rydb. Bull. Torrev Club 29 : 243. 1902.
Xanthoxalis coloradensis Rydb. Fl. Colo. 220. 1906.
Stems erect or nearly so, 1-3 dm. tall, from slender rootstocks, villous or villoushirsute, or nearly glabrous except on the younger parts; leaflets bright-green, the blades 7-20 mm. broad, more or less strigillose and ciliate, especially when young, or glabrous in age ; peduncles overtopping the stem or the branches at least at maturity ; cymes umbellike, usually maturing 1 flower at a time which is accompanied by several drooping buds ; pedicels strigillose, not greatly elongate; sepals 3^1.5 mm. long; petals pale-yellow or lemon-yellow, 9-12 mm. long; filaments glabrous; capsules long-columnar, 12-15 mm. long, or rarely smaller, glabrous, gradually pointed at the apex.
Type locality : Jackson County, Missouri.
Distribution : Nova Scotia to South Dakota, Colorado, and Georgia.

Xanthoxalis stricta (L.) Small, Fl. SE. U. S. 667. 1903
Oxalis stricta L,. Sp. PI. 435. 1753.
orniculala stricta Sav. in Lam. Encvcl. 4: 683. 1797. ? Oxalis Lyoni Pursh, Fl. Am. Sept. 322. 1814. lOxalis furcata Ell. Bot. S. C. & Ga. 1 : 527. 1818.
Oxa ulala Dillenii Trel. in A. Gray, Syn. Fl. N. Am. 1> : 365. 1897. Not Oxalis Dil-
lenii Jacq. 1794.
Stems erect, but elongate and ultimately decumbent, 0.5-5 dm. long, arising from short or occasionally somewhat elongate rootstocks, strigillose, typically densely so, and stout ; leaflets paleor bright-green, the blades mostly 15-20 mm. wide, or smaller on depauperate plants, glabrous or with few scattered hairs and sometimes ciliate ; peduncles longer than the petioles but usually overtopped by the stem or its branches ; pedicels strigillose, not conspicuously elongate ; sepals 4-5 mm. long at maturity ; petals paleor light-yellow, 5-10 mm. long; filaments glabrous, slender; capsules columnar, stout, 16-30 mm. long, rather abruptly pointed at the apex, minutely but closely pubescent.
Tvpk locality : Virginia.
Distribution : Nova Scotia to Wyoming, Florida, New Mexico, and Mexico.

Xanthoxalis interior Small, Fl. SE. U. S. 668. 1903
Stems erect, 3-6 dm. tall, villous, usually densely so; leaflets green, the blades 20-30 mm. broad, or some of them smaller, copiously strigillose and ciliate ; peduncles longer than the petioles, sometimes conspicuously elongate ; pedicels strigillose, not refracted ; sepals 3.5-4 mm. long; petals light-yellow, 6-9 mm. long; longer filaments pubescent; capsules columnar, slender, 8-12 mm. long, finely pubescent, gradually narrowed into the short beak.
Type locality : Benton County, Arkansas. Distribution : Missouri and Arkansas.

Oxalis dillenii, also the southern wood-sorrel, slender yellow woodsorrel, and Dillen's oxalis, is species in the wood-sorrel family Oxalidaceae in the genus Oxalis. Like other Oxalis species, the leaves of this plant resemble clover leaves, with three leaflets. Flowers have five yellow petals that are 4 to 10 millimetres (0.16 to 0.39 in) in length. Leaflets are 1 to 2 centimetres (0.39 to 0.79 in) wide with pointed hairs. Fruits are rather brown and 1.5 to 2.5 centimetres (0.59 to 0.98 in). It is often considered a weed, and can be found worldwide, but likely originated in North America.