owle] 



Cfje Erratfurg ai 330tang. 



830 



are also eaten by the natives of West Tro- 

 pical Africa. 

 OWLER. The Alder, Alnus glutinosa. 



OXALIDACEiE. (Ledocarpece, Rhyncho- 

 tliececv, Hngoniacece, Oxalids.) A natural 

 order of tlialami floral dicotyledons, belong- 

 ing to Lindley's geranial alliance of hypo- 

 gynous Exogens. They are herbs, under- 

 shrubs, or trees, with alternate, rarely op- 

 posite, compound (occasionally simple) 

 leaves, generally without stipules, and are 

 found in hot as well as temperate climates, 

 abundantly in North America, and at the 

 Cape of Good Hope, the shrubby species 

 being confined to the hotter parts of the 

 world. Their symmetrical flowers consist 

 of five persistent imbricate sepals ; five 

 unguiculate petals, with a twisted sestiva- 

 tion ; ten stamens, more or less monadel- 

 phous, in two rows ; and a five-celled 

 ovary, with filiform distinct styles. Fruit 

 capsular, membranous or fleshy, usually 

 five-celled; seeds few, albuminous, at- 

 tached to a central placenta, sometimes 

 with a peculiar elastic integument. In 

 some cases phyllodia or winged petioles 

 occupy the place of leaves. They are often 

 acid in their properties, and some of 

 them yield esculent roots. There are up- 

 wards of 300 species, distributed in about 

 ten genera, of which Oxalis, Averrhoa, and 

 Hugonia are examples. [J. H. B.] 



OXALIDE OSEILLE. (Pr.) Oxalis Ace- 

 tosella. 



OXALIS. A very large genus of Oxali- 

 dacece, of which the greater number of 

 species occur in tropical America and at 

 the Cape of Good Hope. They are herbs or 

 more rarely shrubs, and one, O. scandens, 

 from Mount Quindiu in South America, is 

 a climber ; but by far the greater number 

 have the stem reduced to a rhizome, some- 

 times subterranean, sometimes above 

 ground, often taking the shape of a bulb or 

 forming a tuber. In these the leaves are all 

 produced in a tuft. In some of the bulbous 

 species, as O. cernua, bulbs are also produ- 

 ced in the axils of the leaves. The leaves of 

 most of the species consist of three entire 

 leaflets which are usually inversely heart- 

 shaped, and occasionally slightly sensitive, 

 as in O. stricta. Sometimes the leaflets are 

 reduced to two, or even to one, when the 

 leaf appears to be simple ; and Anally a few 

 have even this solitary portion deficient, 

 which occurs in such species as O.fruticosa 

 and 0. leptopodes, which have flat dilated 

 leaf-like petioles. The leaves contain an 

 acid juice. One section of the genus {Bio- 

 phut am) has pinnate leaves,with many pairs 

 of pinna?, but no terminal leaflet. In one 

 of these, from India, O. sensitiva, these 

 compound leaves are nearly as sensitive as 

 in tiie sensitive plant, for they contract on 

 the slightest touch. The peduncles (scapes 

 in the acaulescent species) are generally 

 terminated by an umbel of brightly co- 

 loured flowers, the pedicels of which are 

 bracteated. The flowers consist of five se- 

 pals, free or combined at the base ; five 

 petals ; ten stamens, the five outer ones 



smaller, the filaments combined at the base 

 (except in Biophytum) ; live styles ; the cap- 

 sule ovoid or oblong, often five-sided ; the 

 seeds covered by an elastic coat, which 

 ruptures when they are ripe, and by its 

 contraction expels them with considerable 

 force. 



Three species occur in Britain. One of 

 these, the common Wood Sorrel, 0. Aceto- 

 sella, has a scaly rhizome with a tuft of 

 leaves at the top, and solitary white flowers- 

 more or less veined with purple. This 

 plant has a pleasant acid taste from con- 

 taining binoxalate of potass ; and hence it 

 j was once used in medical practice as a re- 

 | frigerant in fever, and an antiscorbutic in 

 i scurvy, and still remains in the London 

 i Pharmacopoeia, though fallen into disuse. 

 The other British species, 0. corniculata 

 j and O. stricta, are caulescent. 0. Acetosella 

 I is said to be the Shamrock of Ireland, 

 though some prefer Trifolium, and other 

 | plants have been suggested. 



0. crenata has an erect leafy stem and 

 umbellate flowers, which are yellow streak- 

 ed with purple. It is a native of Peru, and 

 is largely cultivated about Lima for its 

 very acid leafstalks ; it also produces yel- 

 lowish tubers of the size and shape of 

 j small potatos, and having a slightly acid 

 flavour, which disappears on boiling. When 

 introduced into this country it was expect- 

 ed that it would have proved a valuable 

 substitute for the potato, but this, however, 

 has not been realised, the tubers being in- 

 sipid and the produce small, not exceeding 

 half a pound from a plant. 



O. Beppei, from Mexico, a stemless spe- 

 cies, with four leaflets, red flowers, and a 



Oxalis Deppei. 



large scaly bulb, produces fleshy edible fu- 

 siform roots of moderate size. O. tuberosa, 

 from Bolivia, where it is called Oca, is culti- 

 vated in its native place for its potato- 

 like tubers. [J. T. SJ 



OXERA. A genus of Yerbenacea, con- 

 taining a single species from New Cale- 

 donia. It is a branching glabrous shrub, 

 with opposite shortly petiolate leaves, and 



