RHIZOCARPE^ 



35, 



the procumbent stem. According to Juranyi, each Sporocarp is the 

 lit of the coalescence of two segments of bifid leaves. The wall of 



sporocarp is very thick and hard, and consists of several layers of 

 s forming a sclerenchymatous tissue. It is divided by vertical walls 

 I compartments, varying from two to four in the different species. 

 ;h compartment has, at least in its young state, an opening at the 

 X, and is therefore not of endogenous origin, but rather a depression 

 he surface. In each compartment there is, on the side which forms 

 outside wall, a cushion-like placenta, formed from superficial cells, 



resting on a ' vascular ' bundle. To this placenta are attached a 

 iber of ^talked sporanges of both kinds, constituting a sorus \ the 

 ;asporanges are chiefly below, 

 the microsporanges above. 

 ; remainder of each compart- 

 it is occupied by a delicate 

 i-walled parenchyme, Wherx 

 ure the sporocarp splits from 

 apex downwards into as many 

 'es as it has compartments ; 



each sporange dehisces by 



expansion of the gelatinous 

 ;s resulting from the dissolu- 

 i of the tapetal cells. 

 The sporocarps of Marsilea 



capsules with somewhat the 

 pe of a bean, a longer or 

 rter pedicel, and a very hard 

 TCnchymatous wall. They 

 ng, usually in clusters, from 



petiole of an ordinary leaf. 

 ; pedicel runs along the dorsal edge of the sporocarp, and gives 

 lateral veins right and left which branch dichotomously and run to 



ventral edge. The ripe sporocarp has a bilaterally symmetrical 

 cture, and is divided by transverse walls into two rows of compart- 

 its, each of which has, when young, a narrow opening on the ventral 

 ;. Each compartment contains a single sorus, consisting of a few 

 jasporanges in the centre, with a larger number of microsporanges on 

 ti side. As in Pilularia, a large portion of the cavity of each compart- 

 it is occupied by a succulent parenchyme. 

 The development of the sporanges commences, in both genera, with 



swelling up of some of- the epidermal cells of the part which 

 mately becomes the placenta. These cells divide several times 



Fig. i8. — Transverse section of sporocarp oi Pilu* 

 laria. globuli/era. fnz, microsporanges ; ma, 

 megasporanges ; e, wall of sporocarp ; £-, paren- 

 chyme. (After Goebel, magnified.) 



