18 Mr. Brown’s Account of a new Genus of Plants, 
and considering the foliaceous scales which cover the unex- 
panded dower, both from their indefinite number and imbri¬ 
cate insertion as bracteae, and consequently the floral envelope 
as simple, its comparison with the families of this primary divi¬ 
sion would be limited to such as are apetalous ; either absolutely 
as Asarince', those of a nature intermediate between the apetalous 
and polypetalous, in which the segments of the perianthium are 
generally, though not always, disposed in a double series, as 
Passiflorece , Cucurbitacece and Homalince; or those which have 
a simple coloured doral envelope, but are decidedly related to 
polypetalous families, as Sterculiacece. 
With Asarince , the only truly apetalous order to which it seems 
necessary to compare it, Rajfiesia has several points of resem¬ 
blance, especially in the structure of the central column. In 
Aristolochia the antherae, though only six in number, are in like 
manner sessile, and inserted near the apex of a column formed 
by the union of stamina and pistillum. The mere difference in 
the number of stamina seems to be of no importance in the pre¬ 
sent question, there being twelve in Asarum ; and in Thot tea, a 
genus certainly belonging to this family, though referred by 
Rottboll to Contortce*, the stamina are not only still more nu¬ 
merous, but are disposed in a double circular series one above 
the other; an arrangement which may perhaps be considered 
analogous to the concentric series of processes in the apex of the 
column of Rajfiesia. 
In all these genera of Asarince and in Bragantia of Loureiro, 
which is also referable to the same order, the flowers are herma¬ 
phrodite ; but in Cytinus, which, if not absolutely belonging to 
this order, is at least very nearly related to it, they are diclinous. 
The affinity is also in some degree confirmed by the appear¬ 
ance of the inner surface of the tube of the perianthium of some 
* Thottea grandifiora. Rottboll in Nov. Jet. Soc. Reg. Ilafn. ii. p. 529. tab. 2. 
Asarince , 
