76 DESCRIPTIONS OF N.Z. FERNS. 



rhomboidal, tri or quadri-pinnate, and of a rather light green colour. The lower 

 pinnae are rhomboidal in shape, the lower side however being wider than the upper one; 

 the higher pinna more lanceolate. They all branch right and left in pairs, and slope 

 upwards. Pinnules oval or sub-lanceolate, and cut down nearly or quite to their 

 costae into triangular or fan-shaped segments, divided into two or three lobes. The 

 sori are terminal on the lobes, the end of which is prolonged, so as to proje6l a little 

 beyond the involucre on both sides. Though this fern has only been found on an 

 outlying island, it may occur on the main land near the North Cape, and is worth 

 looking for. No one, I believe, has yet cultivated it, but it would no doubt grow 

 freely, like those to- which it is allied, and would probably require less moisture than 

 the other New Zealand Davallias, though the climate of the Three Kings is a humid one. 

 It is allied to D. pyxidata and D. Canariensis. 



GENUS CYSTOPTERIS. (Sis-top-ter-is.) 



" BLADDER FERNS." 



This genus has the sori globose on the backs of the veins. The involucres are 

 membranous, and sub-orbicular, being attached to the frond by a broad base beneath 

 the sorus, over which they bend so as, at first, to cover it like a hood, and give it the 

 appearance of being enclosed in a bladder. As the sorus developes, however, the 

 edges lift, and the hood is pushed back so as to allow the capsules to be seen around 

 the sides and end of the involucre, but not next its base. 



CYSTOPTERIS FRAGILIS. (Sis-top-ter-is fra-gil-is.) 



" BRITTLE BLADDER-FERN." 

 PLATE XVIII., Nos, 5 and 5a. 

 This is one of the ferns common to New Zealand and England, though there are 

 greater variations in its shape in the former, owing to the greater range of altitude and 

 temperature. The North Island plant, shown in figure 5, is scarcely, if at all, 

 distinguishable from the more divided forms of the English one, but in the Middle 

 Island it becomes longer and narrower, and at high levels assumes the stunted 

 appearance indicated in 5a, which is drawn from a specimen gathered by 

 Professor Kirk, in the upper Waiau Valley, at an altitude of 4500 feet. It has an 

 erefil rhizome, which has a tendency to branch and produce several crowns, thus 

 ultimately spreading over a considerable space. The stipes is rather long, slender, 

 smooth and brittle, with a few small scattered scales towards the base. Rctchis and 

 costae the same, but without scales. Frond lanceolate. Pinnae and secondary pinnae 

 deltoid or lanceolate, and alternately arranged. Pinnules more or less narrowly fan- 

 shaped or oval, and divided into pointed lobes. The sori are very numerous, placed 

 on the middle of veinlets running into the lobes ; and as they develop, they become 

 confluent, and nearly cover the under-surface of the frond with their black capsules. 



