134 BRITISH BOTANY. 



OXALIDACE^, DC. The Wood-Sorrel Family. 



Annual or herbaceous plants, with trifoliate leaves and regular 

 flowers, on axillary or radical peduncles. Herbage more or less 

 acid; hence the name. Sepals 5, more or less united at the 

 base, persistent, imbricate in prefloration. Petals 5, free, or only 

 slightly united by their claws, caducous, twisted in prefloration. 

 Stamens 10, united at the base in 2 rows, the 5 opposite to the 

 petals shorter than the others. Anthers 2-lobed, introrse. Ovary 

 free, consisting of 5 carpels. Ovules attached to the inner angles 

 of the cells. Styles 5, free or united at the base. Stigmas 5, 

 cleft or laciniate. Fruit capsular, membranous, 5-celled, many- 

 seeded, rarely one-seeded, 5- or 10-valved. Seeds pendulous, 

 usually enclosed in an aril (see Euonymus) . Embryo straight or 

 slightly curved, covered by the perisperm. Radicle directed to- 

 wards the hilum (at a distance from it) . 



OxALis, Lin. — Caulescent (with a stem) or stemless plants, 

 with obcordate, plicate leaflets, and white or yellow flowers. Se- 

 pals and stamens united at the base. Capsule membranous-her- 

 baceous, oblong or obovate, with 5 lobes. Seeds compressed, 

 striated, in a succulent envelope, which becomes membranous by 

 desiccation (drying), and opens longitudinally when ripe. 



O. Acetosella, Lin. Wood-Sorrel. — e.b. 762. l.b.s. 243. 

 A. 18. C. 81. Lat. 50-60°. Alt. 0-1300 yds. Tern. 51-34°. 



Root creeping, branched, with several small scaly (scale-like?) 

 tubers. Leaves all radical, stipulate; leaflets obcordate, hairy. 

 Peduncles radical, one-flowered, pubescent, with two small bracts 

 about their middle, 2-5 inches high, erect in flower, drooping 

 when in fruit. Corolla ivhite, with 'purple or bluish veins, three 

 times as long as the calyx. Capsule ovate ; seeds shining. 



In woods and shady places. Perennial ; April, May. On Ben 

 Lawers, Perthshire, it was in flower in the middle of July, 1856. 



O. stricta, Lin. Erect Yellow Wood-Sorrel. — Reich. 4895. 

 l.b.s. 244*. 



Alien ; reported from Devon and Cornwall. 



Stem usually erect, simple or rarely branched, not rooting, with 

 underground stolons. (Perennial?) Leaflets notched, without 

 stipules. Sepals linear, bearded at the summit. Petals twice as 

 long'as the sepals. Stigmas capitate. Capsule oblong, tapering, 

 5-angled, with some hairs. 



