320 



FILICALES 



[CH. 



but the sori agree with those of Angiopteris except in their greater length 

 and in the larger number of sporangia. 



Marattia. This genus, which extends " all round the world within the 

 tropics 1," includes some species which closely resemble Angiopteris, while 

 others are characterised by more finely divided leaves with smaller 

 ultimate segments. The fleshy stipules occasionally have an irregularly 

 pinnatifid form (fig. 241, B). The sporangia are represented by oval 

 synangia^ (fig. 245, A ; the black patches at the ends of the lateral veins) 



Fig. 245. A. Marattia fraxinea. A'. A single synangium showing the two 

 valves and pores of the sporangial compartments. 



B, B'. it/. Kaulfussii. 



C, Kaulfussia (synangium showing pores of sporangial compart- 

 ments). 



D, B. Marattiopsis Milnsteri. 



(C, after Hooker; D, E, after Schimper.) 



composed of two valves, which on ripening come apart and expose 

 two rows of pores formed by the apical dehiscence of the sporangial com- 

 partments (fig. 245, A', B). In Marattia Kaulfussii the sori are attached 

 to the lamina by a short stalk (fig. 245, B, B') and the leaf bears a close 



1 Hooker and Baker (68) p. 440. 



2 The term synangium is applied to sporangia more or less completely 

 united with one another and producing spores in groups separated by walls of 

 sterile cells. A synangium may be regarded as a spore-forming organ produced 

 by partial sterilization of sporogenous tissue or as a group of coalescent sporangia. 



