ILLUSTRATIONS OF INDIAN BOTANY. 161 
bursting elastically. Albumen between cartilaginous and fleshy. Embryo straight, as long as 
the albumen: radicle long; next the hilum: cotyledons foliaceous.— Leaves compound (or by 
abortion simple), alternate, seldom opposite or whorled.” 
Arrinitizs. The affinity of this with the three preceding orders, has been already 
adverted to. Formerly it was united with Geraniacee, and is still considered by some not 
sufficiently distinct. DeCandolle however thinks it more nearly allied to Zygophyllee, though 
quite distinct. Its compound leaves and albuminous seed in both of which respects it differs 
from Geraniacee but associates with Zygophyliew, seem to confirm this view. 
Grocrapuicat Distaisution. The genus Oralis is principally confined to the Cape of 
Good Hope and America, but is also though sparingly met with in Europe, Asia, and New Hol- 
Jand. The genus Averhoa is confined to India and the adjoining islands: of Biophytum one 
species is found in the West Indies and the rest in India. 
Properties AND Uses. Acidity is the predominating quality of this order. The Oxalis 
acetosella or wood sorrel, is well known in Europe, and esteemed on account of its cooling and 
refreshing properties, the expressed juice of which furnishes, when crystalized, the so-called 
essential salt of Lemons, or binoxalate of potash. Both species of 4verhoa, namely, 4. Caram- 
bola and 4. Bilimbi, are equally well known on account of their intense acidity. ‘The kind of 
acid which imparts the taste I have never seen mentioned, but presume it is oxalic, the one 
which predominates in the family. The fruit of the former is considered cooling and aperient. 
Remarks ON Genera AND Sprcizs. Originally two genera only were referred to this 
family, Ovalis and Averhoa. The former of these DeCandolle split into two, more perhaps, on 
account of the marked difference of habit than from any well marked differences of structure. 
The principal points of difference consist in the filaments, being free to the base in the one 
( Biophytum ) while they are united into a tube nearly half their length in the other ( Ova/is ). 
They also differ in the form of their fruit, the former having its capsules approaching to 
globose, while in the latter they are cylindrical. These distinctions, added to the very marked 
difference of habit have induced me to revert to DeCandolle’s division, from which we departed 
in the Prodromus. The species of the genus Biophytum are of difficult discrimination, and it 
has been doubted whether there are more than one in India—on this point I now feel quite 
Satisfied, and think we may certainly acknowledge two, I think several species. Supposing we 
fix upon the former number there can be no difficulty in distinguishing them, the one being 
marked by having a single terminal tuft of leaves on a more or less elongated simple un- 
branched palm-like stem—the other, by having a diffuse ramons proliferous stem, each branch 
terminating in a tuft of leaves. The various forms might then be ranged under these, as so 
many varieties. The difference of habit and station which some of these forms affect seem to 
stand in opposition to this extent of simplification, for example—Biophytum sensitivum 
is only found on the plains usually in very open ground exposed to the full blaze of the sun’s 
light, whereas, the form figured in plate 62 is only found in cool alpine situations under the 
shade of thick jungles, both here and in Ceylon. These circumstances may induce the belief 
that the plant is the same, only altered by local circumstances, an opinion which, if urged, I con- 
fess I have not the means of controverting, since it can only be set aside by making the two 
ge change places, and in that way determining whether or not their forms would alter also. 
he B. sensitivum is further distinguished by being glabrous, while the other is very generally 
clothed with hairs, sometimes, especially on the rachis of the leaves and peduncles, very 
densely. This character, however, is not sufficiently constant in either form to admit of much - 
_ weight being attached toit. Of the palm-like forms there are again two varieties distinguish- 
- able by the form of their leaflets —the form fig. 8 in plate 62 represents the one, that of fig. 1 
nearly corresponds with the other, though not taken from it—fig. 8 isa slightly magnified leaflet , 
of B. Candolianum—fig. 10 is that of a species to be afterwards mentioned, but, with the. 
exception of its being a little more tapering and Jess distinctly mucronate at the point, gives a 
pretty good idea of the form of Dr. Arnott’s B. (Oxalis) nudum, and will assist in distin- 
guishing these two perhaps too nearly allied species | “ a ee 
