r > 8 OXALIDE^E. [Oxalis. 



ORD. 18. OXALIDE^:. D C. Wood-Sorrel Family. 



Sepals 5, sometimes slightly combined, equal, persistent. 

 Petals 5, equal, unguiculate, sometimes cohering at the base, 

 aestivation contorted. Stamens 10, more or less monadelphous; 

 the 5 opposite the petals longer: anthers 2-celled. Ovary with 

 5 angles, and 5 cells. Styles 5, filiform ; stigmas somewhat 

 capitate. Capsule membranaceous, 5-celled, 5 10-valved. 

 Seeds few, fixed to a central axis, ovate, striated, included in a 

 fleshy arillus, which opens with an elastic force, and ejects the 

 seed. Albumen between cartilaginous and fleshy. Embryo 

 with foliaceous cotyledons and a long radicle pointing to the 

 hilum. Herbs or shrubs, of various parts of the world* Leaves 

 mostly alternate, rarely opposite or whorled, compound, or, by im- 

 perfection, simple. 



1. OXALIS. Linn. Wood- Sorrel. 



Calyx 5-parted. Petals 5, often united by the base of their 

 claws. Filaments often combined below, 5 outer ones shorter. 

 Capsules angular, 5-celled : cells 2, or many-seeded. Seeds 

 with an elastic arillus. Name from ogvs, sharp or acid. Our 

 species produce in their leaves oxalic acid, in the state of bi- 

 noxylate of Potash. (Professor Thomson.} 



Decandria. Pentagynia. 



1. O. Acetosella, Linn. Common Wood-Sorrel. Leaves all 

 radicle, ternate ; leaflets inversely heart-shaped, hairy ; scape 

 single-flowered ; root scaly. Br. PI. 1. p. 211. E. Fl. v. ii.p. 

 323. E. Bot. t. 762. 



Woods and hedge banks, also on mountains among shady rocks. A 

 beautiful variety, with red flowers, of which I have plants in the Col- 

 lege Botanic Garden, was found by Mr. J. Drummond near Passage, 

 County of Cork. Fl. May, and much later on elevated situations. 

 %. Leafstalks long and slender, reddish. Leaflets drooping at 

 night. Scape with two scaly bracteas. Flowers handsome, drooping, 

 generally white, with purple veins. The leaves have a most agreeable 

 acid flavour. Mr. Bicheno, in a paper published a few years ago in 

 the First Volume of the Journal of the Royal Institution, states it to 

 be his opinion that the wood sorrel ( Oxalis Acetosella) was the an- 

 cient shamrock, as old authors say it was a sour indigenous plant, show- 

 ing itself on St. Patrick's day, and was eaten ; and, therefore, con- 

 cludes, that the Trifolium repens, or common white clover now used, 

 could not have been the plant in former use. The wood sorrel having 

 trifoliate leaves as well as the white clover, would answer as well for the 

 purpose intended. 



SUBCLASS II. CALYCIFLORA. De Cond. 

 Sepals more or less combined into one piece. Petals dis- 



