66 



GYMNOGRAMMOID FERNS 



[CH. 



tion, though these are only slight (Fig. 626). The mature sporangium has 

 a short stalk of variable structure. It may be three-rowed, or it may consist 

 of four to six rows of cells. The annulus is also variable: the chain of cells 

 sometimes runs obliquely past the insertion of the stalk, though its induration 



J) 



Fig. 624. A — C = L/avea cordifolia Lag. ^ = habit. ^ = sterile pinna with venation. C= part oi 

 a fertile pinna, the left-hand flap flattened out to show the venation. D, E ^ Cryptogramme R. Br. 

 Z' = part of a fertile pinna with venation and sori: on the left the margin is flattened out. E = 

 C.japojuca (Thunb.) Prantl, sterile pinna. {D, after Luerssen, the rest after Diels.) 



