42 



THE HABIT AND THE HABITAT OF FERNS 



[CH. 



Fi". 47. Asplenium Cderach, Willd. Two pinnae seen from below, showing on the 

 right the covering of scales, on the left the sori and nervation with the scales 

 removed. (x8.) (After Luerssen.) 



Fig. 48. Vertical section through the scales covering the rhizome of 

 Phlebodium auremn, showing their elaborate overlapping. ( x 35). 



the pinnae, as in Notholaena simiata or ferruginea, or in Jamesonia, with or 

 without the addition of a felt of hairs such as occurs 

 \nN. lanuginosa. These xerophytic characters appear 

 in Ferns exposed to drought either in actual dry 

 areas, or on rocks, or where from their position as 

 epiphytes they are without direct access to the soil. 

 Another form which xerophytic specialisation 

 may take is succulence of the stem or leaf, some- 

 times with a smooth surface and well-developed 

 epidermis, but oftener with more or less numerous 

 scaly hairs. This is seen in Drymoglossiim subcor- 

 datum, where the barren leaves are elliptical and 

 fleshy (Fig. 49). But in other cases the storage of 

 water may be in the distended stem, while the Fig- 49- Shoot of Drymo^los- 



•' .... sumsubcordatiim-sX\.QxK^nni\.. 



leaves are leathery, as in PJwtinopteris. Peculiar (Nat. size.) 



