408 NYMPHALES. [Hypogynous Exogens. 



Alliance XXXI. NYMPHALES.— The Nymph al Alliance. 



Diagnosis. — Hypogynous Exogens, with dichlamydeous flowers, axile or sutured placenta, 

 00 stamens, and an embryo on the outside of a large quantity of albumen ; or, if 

 exalbuminous, the seeds have a very large plumule. 



The singular fact of the embryo lying on the outside of a large mass of albumen 

 would enable the Botanist to distinguish Nymphals with certainty from all those Orders 

 with which they are here associated, if it were not for the Waterbeans, which appear to 

 have no albumen at all. With them, however, it would seem as if an enormous plumule 

 compensated for the absence of this substance. The species are among the most highly 

 developed of any in the vegetable kingdom, if we only regard their flowers ; but the 

 total absence of a woody stem places them, on the other hand, among less noble allies. 

 They differ from the Ranal Alliance principally in their embryo, and seem to run close 

 upon the Crowfoots themselves, through both the Waterbeans and Watershields. They 

 have no obvious alliance with any part of Guttiferals, except Guttifers themselves ; but 

 they touch the Ranal Alliance at every point. 



The stamens are often attached to the sides of the ovary, and are even not liberated 

 in some cases till the very summit of it ; but this seems a mere modification of the 

 hypogynous structure. 



Natural Orders of Nymphals. 



Carpels united into a many-celled fruit, with dissepimcntal placentae. 148. Nymph^bace.e. 



Carpels distinct. Albumen copious. Torus absent 149. Cabosibace.e. 



Carpels distinct. Albumen 0. Torus honey-combed, very large. . 150. Nelumbiace.e. 



Consult a long memoir on the structure of the axis of Nympbfeacese, by Trecul, 

 in Ann. Sc. 3. ser. I V. 286. 



