nosum burns like a torch, and gives out an agreeable odour. The root 

 of Geranium maculatum is considered a valuable astringent in North 

 America, where it is sometimes called Alum root. Barton, 1. 155. In 

 North Wales Geranium Robertianum has acquired celebrity as a remedy for 

 nephritic complaints. Ibid. Some of the Pelargoniums are acidulous, but 

 this genus is chiefly known as an object of garden culture, for which its 

 great beauty, and the facility with which the species tor supposed species 

 intermix, render it well adapted. 



Examples. Geranium, Monsonia, Erodium. 



CXXIII. OXALIDE.E. The Woodsorrel Tribe. 



OxALiDE^T-, Dec. Prodr. 1. C89. (1824) ; Lindl. Syiiops. 59. (182!).) 



Diagnosis. Polypetalous dicotyledons, with definite hypogynous sta- 

 mens distinct except at the base, concrete carpella, an ovarium of several 

 cells with the placentae in the axis, an imbricated calyx, symmetrical 

 flowers, indefinite exalbuminous seeds with a straight embryo, and com- 

 pound leaves. 



Anomalies. 



Essential Chabacter — Sepals 5, sometimes slightly cohering at the base, persist- 

 ent, equal. Petals 5, hypogynous, equal, unguiculate, with a spirally-twisted estivation. 

 Stamens 10, usually more or less monadelphous, those opposite the petals forming an inner 

 series, and longer than the others ; anthers 2-celled, innate. Ovarium with 5 angles and 5 

 cells ; styles 5, filiform ; stigmata capitate or somewhat bifid. Frtdt capsular, membranous, 

 with 5 cells, and from 5 to 10 valves. Seeds iew, fixed to the axis, enclosed within a fleshy 

 integument, which curls back at the maturity of the fruit, and expels the seeds with elastic 

 city. Albumen between cartilaginous and fleshy. Emlryo the length of the alinimen, with 



a long radicle pointing to the hilum, and foliaceous cotyledons Herbaceous plants, tinder' 



shrubs, or trees. Leaves alternate, com{)ound, sometimes simple by abortion, very seldom 

 opposite or somewhat whorled. 



Affinities. Formerly included in Geraniacese, from which, in the 

 judgment of many, they are not sufficiently distinct. According to M. 

 Decandolle they are rather allied to Zygophyllecc ; an opinion in which I 

 am inclined to concur, and which their compound leaves appear to confirm. 

 Averrhoa differs from the rest in its arborescent habit. They are generally 

 described with an arillus; but, according to M. Auguste St. Hilaire, the 

 part so called is nothing but the outer integument of the seed. PI. Us. 43. 



Geography. Natives of all the hotter and temperate parts of the 

 world, most abundantly known in America and the Cape of Good Hope, 

 and most rarely in the East Indies and equinoctial Africa. 



PuoPEUTiES. Averrhoa Bilimbi and the pinnated Oxalis called Bio- 

 phytum have sensitive leaves. Their foliage is generally acid, so that they 

 are fit to supply the place of sorrel. Some of the species are astringent, 

 and have been employed in spitting of blood. Oxalis acetosella contains 

 pure oxalic acid. Turner, 623. Several species of Oxalis arc used in 

 Brazil against malignant fevers. PL Usttellcs, 4^. The fruit of Averrhoa 

 is intensely acid. A species of Oxalis found in Columbia bears tubers like 

 a potato, and is one of the plants called Arracacha. 



Examples. Oxalis, Biophytum, Averrhoa. 



