MR. BENTHAM’S NOTES ON HOMALIUM. 31 
Notes on Homalium. By Gzonez Вкнтнїм, Esg., V.P.LS. 
[Read June 2nd, 1859.] 
In the revision of the "Hong Kong Flora,’ with which I have been 
lately occupied, I had occasion to investigate the validity of the 
genus Blackwellia, of which an elegant Chinese species was many 
years since introduced into our gardens, and has found its way 
into catalogues and botanical works under six different names. 
The result of this investigation has been the conviction that the 
genus must altogether be united with Homalium. I could not, 
however, come to this conclusion without a careful examination of 
all the species referred to both genera of which we had specimens; 
and as I also found several unpublished ones in the herbaria at 
Kew, I have been led to draw up a short synopsis of the whole 
group, which I now beg to lay before the Society. 
The genus Blackwellia was originally established by Jussieu 
and Lamarck on two or three Mauritius trees which differed from 
the only two Homalia then known, both from South America, in 
having only one instead of three stamens opposite each petal (or 
inner segment of the perianth as it was then called). Ventenat 
afterwards added two or three eastern species having the same 
peculiarity ; and De Candolle, in the 2nd vol. of the * Prodromus,' 
maintained the two genera, with the same technical character as 
well as geographical distinction. Since then, several Asiatic 
species with two or more stamens to each petal have been de- 
scribed, and yet they have been published as Blackwellias. An 
exception, has been made in the case of the African Homalium 
angustifolium, which has the character of the American ones; 
and Sir James Smith, who always closely adhered to generic 
character, published it accordingly as a Homalium. Modern 
botanists, however, applying too literally the rule of “ character 
non facit genus,” appear in this instance to have practically 
adopted geographical origin as the sole basis of the limitation 
of the two genera. Some other characters are indeed indicated 
by Endlicher and others, such as the supposed larger calycine 
Segments or capitate stigmas of the American ones; but none 
of them will bear the test of examination. And few, I believe, 
would now contest the generally admitted rule in systematic 
botany, that geographical origin without any character is not 
to be recognized as a generic distinction. It therefore becomes 
necessary to unite the Asiatic clustered-stamened species with 
the corresponding American Homaliwms. As some of these, again, 
in other respects resemble the single-stamened species more than 
