114 



GERANIACE^E. 



is applicable are so numerous and the plant everywhere so common, one 

 is led to wonder that it is not more generally employed. 



OX ALIS. —Wood-Sorrel. 



Character of the Genus. — Sepals 5, distinct or united at the base, im- 

 bricate, persistent. Petals 5, sometimes united at the base, withering. 

 Stamens 10, more or less united at the base, those opposite the petals 

 longer than the others ; anthers versatile. Ovary of 5 united carpels, not 



beaked ; styles distinct. Fruit a 

 5-celled, 5-angled capsule opening 

 by as many valves, each cell 2- 

 seeded. 



Herbs, either annual or with a 

 tuberous or creeping perennial rhi- 

 zome. Leaves alternate or radical, 

 palmately trifoliate. 



Oxalis Acetosella Linne. — 

 Wood-Sorrel. 



Description. — Calyx : sepals 

 small, ovate, obtuse. Corolla : pet- 

 als obovate, unguiculate, one-half 

 inch long, white with reddish 

 veins. Capsule ovoid. Perennial. 

 Root-stock creeping, slender, scaly 

 toothed. Leaves all radical on long 

 petioles ; leaflets broadly obcor- 

 date. Scapes 2 to 5 inches long, 

 1-flowered, appearing in June, 

 the Alleghanies northward ; also in 



Fig. 116.— Oxalis Acetosella. 



Habitat. — In cold woods from 

 Northern Europe and Asia. 



Oxalis striata Linne. — Yellow Wood-Sorrel, Sheep-Sorrel. 



Description. — Flowers similar in structure to the preceding, but smaller 

 and borne upon 2- to 6-flowered, axillary peduncles, yellow. Capsules elon- 

 gated. Annual, or by means of subterranean shoots, perennial. Stem erect, 

 leafy. Flowers appear throughout the summer. 



Habitat. — Common in waste and cultivated grounds. 



Part Used. — The leaves — not official. 



Constituents. — All plants of this genus have, to a greater or less extent, 

 an agreeable acidulous taste due to the presence of binoxalate of potash, 

 their only important constituent. This salt was formerly extracted from 

 certain species of oxalis and was sold under the name of salt of sorrel^ but 

 it is now prepared from oxalic acid and potash. 



Preparations. — There are none, save the commercial binoxalate of pot- 

 ash, and, as above stated, this is no longer prepared from the plant. 



