i8 The Irish Nattiralisi. l^ebmafy, 



F. OVATUM (fig. 2). 



Most developed lobes ovate to Imiceolaic, deeply divided into 

 lanceolate segments ; distinctly stalked, the footstalks and 

 tertiary rachis not winged. 



Viewed against the light, this form, while the amount 

 of its subdivision may nearly equal that of the preceding, 

 is seen to be not nearly so lacy in appearance : the greater 

 breadth of the lobes giving it a heavier appearance, and the 

 narrowness of the footstalks making a sharp contrast between 

 the stem and leaf subdivisions. The tips of the frond and 

 pinnae are not so attenuate as in the preceding plant. 



To this form belong specimens which I have seen from 

 Lough Hyne (R. A. Phillips) and Schull (R. D. O'Brien) in 

 Cork ; Snowhill, in Kilkenny ; and Newtownards in Down 

 (both Praeger). It is the plant of Moore's " Nature-printed 

 Ferns " (plate xxxvii. B., and description), of Lowe's 

 " Ferns British and Exotic " (vol. v., p. 75) and " Our 

 Native Ferns " (vol. ii., fig. 514), of Newman's " British 

 Ferns "(ed. 3, p. 227, middle figure only), and of Britten's 

 " European Ferns," p. 108 (not p. 106). 



Following on these extreme forms come others which, 

 being fully tripinnate with caudate tips to the fronds and 

 pinnae, come within Bory's definition of acutum, although 

 Irish botanists, rendered fastidious by acquaintance with 

 the extreme forms of south-western Ireland, might be in- 

 clined to deny them that rank. Here belongs, for instance, 

 the Glendalough plant which originated this long dis- 

 quisition. Hooker's figure (Plate 33, i.) in his " British 

 Ferns," approaches var. acutum f. ovatum but is not extreme 

 enough to be placed under the variety. 



Following again on these, forms occur in many parts of 

 Ireland (and elsewhere) which constitute a chain extending 

 from the least divided forms of acutum through typical 

 Adiantum-nigrum to var. obtusum (fig. 3), with ver}^ broad 

 blunt and little-divided pinnae and pinnules. 



Returning to var. acutum, it is to be noted that it is 

 essentially a shade plant, and seems especially partial to 

 dry rocks in sheltered places. This chosen habitat is no 

 doubt in part responsible for the very long stipe (often twice 



