DESCRIPTIONS OF N.Z. FERNS. 135 



Colenso disputes the plant being the real N. cordifolia, and names it " N. flexuosa," 

 on account of some trivial differences between it and the typical N. cordifolia. It is 

 also called " N. tuberosa" (because in some countries the tubers on its roots are large 

 enough to be collected as an article of food), " A. pectinata," " Aspidium cordifolium," 

 and " A. Tuberosum." It is easily cultivated in a greenhouse, and I grew it for some 

 years in a room. It likes light soil, and plenty of watering, but is apt to have a shabby 

 appearance, owing to the pinnae falling off and leaving the rachis bare. The fronds, 

 too, are very often narrowed in the middle, as if they had intended to stop growing, 

 and then started on again. I think this probably arises from changes of temperature 

 occurring during the growth of the frond. 



This fern has creeping wiry rhizomes, which produce tubers and crowns of fronds 

 at intervals. The stipes is short, rather stout, ereft, brown, and slightly scaly. 

 Rachis also stout and brown, smooth, but with a scale here and there. Frond 

 extremely long and narrow, pinnate. Pinnae stalked, close-together, oblong, with 

 rounded ends and rather widened bases. Edges entire or very slightly crenate in 

 fertile pinnae. The pinnae are connected with the rachis by a joint, and thus are very 

 liable to break off. It often happens that some of the lower pinnae have thus fallen 

 off before the apex of the frond has unrolled itself, and they are very apt to drop off 

 in drying, and spoil the look of the specimens. Texture almost membranous ; colour 

 shining yellowish green. The position of the sori is marked by raised dots on the 

 upper surface, and these are often white or nearly so. Sori few, kidney-shaped, and 

 placed almost half way between the costa and edge, with the rounded side towards the 

 apex of the pinna. Involucres also kidney-shaped, large and membranous. 



TRIBE POLYPODIA (Pol-ly-po-de-ae) 



Has the sori on the backs of lobes, round or rarely oblong, not more than twice as 

 long as broad. 



GENUS POLYPODIUM. (Pol-ly-po-de-um.) 

 From " polus " many, " poda " feet, so called because the European Polypody has 

 a creeping rhizome, sending down many short roots. This is the largest genus of any 

 and includes plants of two different modes of growth, each series including a number 

 of species of each of the different kinds of venation, and from all climates. 



What is called the " Desmobryoid " series has the habit and mode of growth of 

 Aspidium, i.e., has the stems contiguous to the caudex, and the sori always on the 

 middle of veins. 



The sub-genus " Phegopteris " has venation like Lastrea, i.e., veins all free. 

 It includes 



