488 



OXALIDACEiE. 



[Hypogynous Exogens. 



Order CLXXXV. OXALIDACE^.-Oxalids. 



Oxalideae, DC. Prodr. 1. 689. (1824) ; Endl. Gen. cclvi.; Meimer Gen. 57.— Ledocarpese, Meym Eeise. 1. 

 307. ; Klotzsch in Linncea 10. 431. ; Endl. Gen. p. 1169.— RhjTicotheceae, Endl. Gen. p. 1169.— 

 Hugoniacese, Amott Prodr. Fl. Ind. renins. 1. 71. (1834) ; Ed. pr, Ixvii. ; Wight Elustr, 1. ; Endl. 

 Gen. p. 1016 ; Meisner, p. 35. 



Diagnosis. — Geranial Exogens, with symmetrical flowers, distinct styles, carpels longer 

 than the torus, and seeds with abundant albumen. 



Herbaceous plants, undershrubs, or trees. Leaves simple or compound, alternate, 

 usually but not always without stipules ; occasionally opposite. Sepals 5, sometimes 



slightly cohering at the base, persistent, imbricated. 

 Petals 5, hypogynous, equal, unguiculate, with a 

 spirally-twisted aestivation ; occasionally 0. Stamens 

 1 0, usually more or less monadelphous, those opposite 

 the petals forming an inner series, and longer than 

 the others ; anthers 2-celled, innate. Ovary with 3 to 

 5 cells ; styles as many, filiform ; stigmas capitate or 

 somewhat bifid ; ovules anatropal. Fruit capsular, 

 membi'anous, or dinipaceous, with 3-5 cells and as 

 many or twice as many valves, if it is dehiscent. 

 Seeds few, fixed to the axis, sometimes inclosed 

 within a fleshy integument, which curls back at the 

 matm'ity of the fruit, and expels the seeds with 

 elasticity. Albumen between cartilaginous and fleshy. 

 Embryo the length of the albumen, with a long radicle 

 pointing to the hilum, and flat cotyledons. 



These plants were formerly included in the Order 

 of CranesbiUs, from which, in the judgment of many, 

 they are not sufficiently distinct. According to De 

 CandoUe, they are rather alhed to Beancapers ; 

 an opinion which theu' compoimd leaves appear to 

 confirm. The species are generally described with an 

 aril ; but, according to Auguste de St. Hilaii'e, the 

 part so called is nothing but the outer mtegument of 

 the seed. The genus Hugonia, which has been placed 

 first in one Order, then in another, and even con- 

 sidered the type of an Order apart from aU others, 

 chiefly differs in its simple leaves and deciduous 

 stipules. The time character of Oxalids resides in 

 theu' regular flowers, beakless fruit, and albuminous 

 seeds, to which may be added the very general tendency 

 among them to form compound leaves. 



Natives of all the hotter and temperate parts of the 

 world, most abundantly however in America and the 

 Cape of Good Hope ; more rarely in the East Indies 

 and equinoctial Africa ; and sparingly in the temperate 

 The shrubby species are confined to the hotter parts of 



V4v 



Fig. CCCXXXVI. 



parts of Asia and m Europe, 

 the world. 



Averi'hoa Bilimbi and the pinnated Oxahs called Biophytum have sensitive leaves. 

 The chief quahty of the typical species of this Order resides in their strong acidity, 

 caused by oxahc acid, formed by them in great abundance ; hence they are used as 

 substitutes for Sorrel. In the Blimbing, and Carambola (AveiThoa Bihmbi, and 

 Carambola), whose fruit is eaten in the East Indies, this acidity is intolerable to 

 Europeans, who use them chiefly as pickles. On the same account several species of Oxa- 

 Us are used in Brazil against malignant fevers. A species of Oxalis (crenata), found in 

 Columbia, bears tubers like a Potato, and is one of the plants called AiTacacha : the 

 tubers are insipid, and not worth cultivation ; the stalks of the leaves are intensely 

 acid, and make an agreeable preserve. Another species, the Oxalis Deppei, has. 



Fig. CCCXXXVI.— Oxalis confertissima. 1. calyx ; 2. stamens ; 3. pistil ; 4. seed and its section of 

 O. acetosella. 



