402 ON APONOGETON. 
On APONOGETON, and the allied Genera; by M. PAKENHAM 
EpcEÉwonrTH,* Esa. 
(With Two Plates. Tass. XVII, XVIII.) 
There appears to be considerable confusion regarding the 
character and limits of the genus Aponogeton, as given 
in works of authority; I therefore beg to offer a few re- 
marks on it, the result of some observations I made on 
two species which I had an opportunity of fully examining 
in India. 
The genus at first consisted of a few species, of which 
A. distachys and A. monostachys are examples, having a bifur- 
cate or simple spadix. To these have been added some 
simple-spiked species from India (Roxb. Fl. Ind. v. 2, P. 
210), and some from the Cape with bifurcate inflorescence, 
while certain Madagascar plants of similar babit have been 
described under the name of Ouvirandra by Thouars (Hydro- 
geton, Pers.)—All these are referred by Endlicher in his 
Genera Plantarum to the natural order of Saururee; appa 
rently on the authority of E. Meyer, in a paper on the 
structure of Houttuynia to which I have not been able to 
refer. E 
On finding the Indian species that I examined (A. mono- 
stachys and undulatus) were both decidedly monocotyledonous 
and belonging to the natural order Naiadee, (though differing 
from the greater part of that Order in having erect seeds and 
an anatropous embryo), I drew up and published in the 
Journ. Asiat. Soc., early in 1842, ashort paper modifying the 
character of the genus Spathium, + to which these and other 
* The present paper was prepared by Mr. Edgeworth, and in our posses- 
sion, long before that on a similar subject by M. Planchon of Mon 
lier, which has just appeared in a recent number of the Annales des 
Sciences Nat. Bot. 1844, p. 107, and which cannot but tend to confirm 
Mr. Edgeworth in keeping Ouvirandra distinct from Aponogeton.—[ED-] 
+ The genus Spathium, as characterized by Loureiro, has no resemblance 
at all to Aponogeton, and probably does belong to the Saururee. 
