The Morphology of Ruppia Maritima. 



71 



considerable modiiication in this way. The period of blooming is 

 at hand, and although no flowers have yet appeared, we find flower 

 buds at the ends of the lateral branches as well as at the termination 

 of the main shoot itself. 



Some of the modifications here exhibited are the varying- orien- 

 tation of nodes and internodes — an arrangement evidently brought 

 about to obtain the most advantageous light, space, &c. ; — the 

 irregularity in length of internodes, those at the base of the plant 

 being not necessarily the longest ; and the number of leaves borne 

 on the branches previous to the development of flowers, for since 

 the latter must bloom above the surface of the water, the lowest 

 branches must necessarily be longer and hence bear more leaves. 



In its development of flower buds, the case is a good illustration 

 of the manner of change from the vegetative branching to the in- 

 florescent type, as described below. 



b. Inflorescent Branch System. 



Irmisch (1851) has 

 accurately described 

 the inflorescent type 

 of branching in R. 

 rostellata, but for the 

 sake of completeness 

 and confirmation in 

 R. maritima, I will 

 review the more im- 



portant pomts. 



When the upright 

 or upward growing 

 branches arrive at or 

 near the surface of 

 the water, their api- 

 ces terminate in in- 

 florescences, as shown 

 diagrammatically in 

 Text-fig. 1, consisting 

 of a slender oeduncle ^ig"J^® 1- — Diagrammatic representation of iniior^ 

 escent branch system ; a and &, stronger and 

 and a rhachis homol- weaker shoots respectively ; /, //, and ///, suc- 

 Ogous to a spadix, the cessive generations of sympodial development ; 

 latter bearing always •^' Ao^er. 



two flowers. From now on the inflorescent type of branching prevails. 

 For from the axil of each of the two nearly opposite leaves sub- 

 tending the peduncle (see p. 97 ff.) arises a secondary branch (Text- 



