Roscndahl: svArPLOCARPUs and lvsiciiiton. 147 



the ovary is sunk in the fleshy axis, but more deeply in Syniplo- 

 carpiis than in Lysichiton. 



In both genera there is a considerable development of tissue 

 from the antipodal cells at the same time that the endosperm is 

 formed. The details of embryology are different in the two.* In 

 Syiiiplocarpiis a short thick suspensor is developed, whereas in 

 LysicJiitoii no such organ is present. The mature embryo of the 

 former is almost spherical, while in the latter it is oblong, slightly 

 bent and is flattened on one side. In Lysichiton there is no en- 

 dosperm and the seedcoat is thin. In Syjiiplocarpus neither en- 

 dosperm nor seedcoats are present, the embr3'0 when mature lies 

 naked in the cavity of the ovary and is protected by the enlarged 

 spadix and the hardened perianth. 



The inflorescences of Syiiiplocarpiis and Lysichiton are quite 

 unlike. In the former it is short, ovoid completely inclosed by 

 the persistent sessile spathe, wdiilst in the latter it is long, cylin- 

 drical and is freely exposed even before anthesis. The long spathe 

 drops oft* very early. 



The anatomy of root, stem and leaf is much the same in 

 both. It does not reveal anything that can be considered of 

 any special significance in considering relationships. The fact 

 that latex ducts are not present in connection with the phloem of 

 the vascular bundles of either genus does not necessarily mean 

 that they are closely related genetically. There are aroids of 

 widely dift'erent relationship in which these structures are lack- 

 ing- 

 All things considered, it appears that the relationship of 



these two aroids is rather remote, especially if one rids himself of 

 the notion that they must be closely related simply because one 

 finds them in juxtaposition in some natural system. If they trace 

 back to a common ancestral branch, which is not at all certain, 

 their separation must have takep place at some very distant 

 time, for the dift'erences in the morphology of renewal shoots and 

 inflorescences appear much more fundamental and significant than 

 the curious similarities in growth and habit which largely seem 

 responsible for the close association of the two genera in system- 

 atic works. The latter are apparently nothing more than inter- 



* Campbell, D. H. Annals of Botany. XIV. p. 1. Rosendahl, C. Otto. Minnesota 

 Botanical Studies. IV. p. 1. 



