ILLUSTRATIONS OF INDIAN BOTANY. 65 
principally distinguished, 
Pen elmoschus appertain to 
the former its segments are distinct, while in the latter they continue to 
i 
characters : by the involucrum for example Malva and Althea are 
he principal distinguishing characters between Hibiscus and 
the calyx, in 
t seems questionable whether it is judicious to take leading generic characters from the 
‘involucrum, Linneus objected to the principle, and laid it down as a rule, that they ought 
always to be taken from the fractification only, by which he meant the calyx and organs 
embraced by it; but in the case of the Malvacee, nearly all of which are referable to his class 
and order Monadelphia polyandria, and also in Umbellifere, he found it convenient to depart 
from his own rule, and got over the difficulty by calling the involucrum an external calyx, 
Dr. Zenker has, (Plante Indice) in his genus Hymenocalyx, our Abelmoschus angulosus, 
carried this departure from the Linnean rule to excess, by founding a genus on the circum- 
stance of the involucrum as well as the calyx occasionally splitting spathaceously, for with that 
exception, which I have since ascertained is not constant, there is absolutely no difference 
between that genus and Abelmoschus, and ought not in my opinion, to be retained. 
e spathaceous involucrum of that species which completely conceals the calyx, led Mr. 
Arnott and myself into a curious error, by inducing the belief that it was the calyx, and that 
the involucrum was so early caducous that we had no opportunity of describing it. . 
The genus Dyctiocarpus which associates wit ida in wanting the involucrum, 
and in having 1I-seeded carpels, I ventured to separate on account of its definite stamens, 
which had previously caused it to be removed from the order and referred to Bytineriacee. 
The curiously reticulated testa of its seed affords another good character, as being one which I 
am not aware of existing in any other species of the order, e genus Decaschistia is re- 
markable for its 10-celled and 10-valved, capsule, with a solitary seed in each cell. For further 
illastrations of the several genera of this rather large and complex order, I must refer to my 
Icones, with the aid of which, I hope to be able to afford most ample illustrations of the genera 
of all the larger and more important orders to be treated of in the course of this work. 
The following additions have been recently made to the order. 
Urena repanda—Of this little known species I gular. The very distinct form and large size, as com- 
have at length got specimens, from Goomsoor (un- pared with the rest of the genus, of the involucel and 
fortunately rather imperfect, ) through the kindness of © labrous exte- 
W. G. Davidson, Esq. I find it does not correspond very 
accurately with the generic character of Urena: neither to 
does the specimen agree well with the character of the 
Species, but as the species of this genus are apt to vary 
considerably in their forms I have no doubt of its being 
e same plant, as it agrees in one or two important 
points. These peculiarities lead to the suspicion that it 
ought to be removed from the genus, though in habit 
it associates ver sely, The most prominent fea- 
tures of distinction between this and the other species 
both the mite 
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enclosing the carpels, which, 
being globose and armed all over with 
acuminated at the point, cordate at the base, repandly 
dentate on the margin, and pubescent on both sides 
with a single gland beneath ; the flowers numerous, the 
eduncles axillary several flowered, and from the abor- 
tion of the leaves, racemose towards the ends of 
the branches. 
hough my specimens are imperfect, yetas this 
plant is very little known, I shall endeavour to have it 
J 
figured in my Icones. 
