502 SYSTEMATIC BOTANY. 



slightly coherent at the base. Petals 5 (Jig. 906), hypogy- 

 nous (Jig. 907), rarely wanting, unguiculate ; cesiivation twisted. 

 Stamens double the number of the petals and sepals {fig. 

 906), arranged in two rows alternating with each other, the 

 inner row longer than the outer {fig. 907) and opposite to 

 the petals ; anthers 2-celled, innate. Ovary superior {fig. 907), 

 3 — 5-celled, with as many distinct styles as there are cells ; 

 stigmas capitate, or somewhat bifid. Fruit usually capsular 

 and 3 — 5-celled, and 5 — 10-valved, occasionally drupaceous and 

 indehiscent; placentas axile {fig. 907). Seeds few, sometimes 

 provided with a fleshy integument, which bursts with elasticity 

 when the fruit is ripe, and expels the seeds; emhryo {fig. 908) 

 straight, in cartilaginoiis fleshy albumen; raclide long, and 

 turned towards the hilum ; cotyledons flat. 



Diagnosis. — Herbs, or rarely shrubs or trees, usually with 

 compound exstipulate leaves. Stems continuous and not 

 separable at the joints. Flowers hypogynous, regular, sym- 

 metrical. Sepals, petals, and stamens with a quinary distri- 

 bution ; the sepals persistent and imbricate ; the petals 

 twisted in sestivation ; the stamens commonly somewhat mon- 

 adelphous {fig. 536), with 2-celled innate anthers. Styles fili- 

 form, distinct. Fruit 3 — 5-celled, without a beak. Seeds few, 

 with abundant albumen, and a straight embryo. 



Distrihitio7i, ^'c. — These plants are generally distributed 

 throughout both the hot and temperate regions of the globe ; 

 the shrubby species are, howcA-er, confined to the former. They 

 are most abundant at the Cape of Good Hope, and in tropical 

 America. Examples of the Genera: — Oxalis, Averrhoa. There 

 are about 330 species. 



Properties and Uses. — Chiefly remarkable for their acid juice, 

 which is due to the presence of binoxalate of potash. They 

 generally possess refrigerant properties. The fruits of some are 

 eaten by the natives in the East Indies, but they are too acid to 

 be acceptable to Europeans, who, however, sometimes use them 

 as pickles. 



Averrhoa BiUmhi and A. Caramhola yield acid fruits, known respectirely 

 under the names of Blimbing and Carambole. They are eaten by the 

 natives in the East Indies, but are too acidulous for Europeans, who never- 

 theless use them for pickles. 



Oxalis.— 0. acetosella, Common Wood-Sorrel, is a common indigenous 

 plant, abounding in woods. It has temate leaves, and is considered by 

 many to be the true Shamrock, as its leaves open about St. Patrick's Day. 

 When infused in milk or water, it forms a pleasant refrigerant drink 

 in fevers. The leaves, taken as a salad, are antiscorbutic. 0. crenata,^ 

 a plant which is called Arracacha, together with others, as 0. Deppei, 0. 

 esculenta, &c.. have edible tubere, which are used as substitutes for potatoes 

 in some districts. 0. anthelmintka, the Mitchamitcho of Abyssinia, has 

 very acrid tubers. These are much employed for their anthelmintic pro- 

 perties in that country, being frequently prefeiTed to Kousso {Brayera 



