130 DESCRIPTIONS OF N.Z. FERNS. 



bluntly-pointed lobes, which, as well as the pinnules themselves, point upwards. Sori 

 numerous, usually in two rows, and very variable in size, being sometimes quite small 

 and at others very large. Involucres membranous^ round and white. Sometimes they 

 are very distinct, and quite cover the young sori, even when these are large, but are 

 afterwards completely hidden among the ripening capsules. Other plants seem to 

 have no involucres at all, whence the fern has sometimes been classed as a Polypodium. 

 Texture harshly coriaceous : colour dark brownish or golden green. It is almost 

 hopeless to grow this fern from portions of the rhizomes, but if a very young plant is 

 carefully taken up, and planted in good vegetable mould, it will thrive well. It will 

 soon, however, outgrow even the largest-sized pot, and have to be transferred to the 

 soil of the fernery, or better still a shady sheltered place in the garden. 



GENUS NEPHRODIUM. (Nef-ro-de-um.) 

 Named from the Greek word " nephros " a kidney, on account of the shape of its 

 involucres. It has sub-globose sori, terminal on veinlets. Involucres heart or kidney 

 shaped, attached by the indented part, technically termed the sinus. 



SUB-GENUS LASTREA. (Las-tre-a.) 

 Has the veins free and veinlets forked. It includes 



NEPHRODIUM THELYPTERIS. (Nef-ro-de-um the-lip-ter-is.) 



" MARSH BUCKLER-FERN." 

 PLATE XIII., No. 3. 



The normal form of this fern is found all over the North Temperate Zone, and was, 

 no doubt, formerly much more common than now. The New Zealand form is what is 

 called " var. squamulosum," on account of its being slightly scaly. It occurs also in 

 South Africa. It is rather local in New Zealand, though more abundant than is 

 generally supposed. This arises from its being sufficiently like other swamp ferns, 

 particularly Polypodium pennigerum, to escape notice among them. Mr. Thomson 

 says " it occurs only in the north end of the North Island from the Bay of Islands to 

 Rotomahana, which is probably its most southerly habitat." It is, however, pretty 

 common in all the swamps on the northern side of Cook's Straits, and I have seen it in 

 similar situations inland up to about 2500ft. elevation ; but, of course, it dies out as 

 the swamps are drained, since it only grows in the sphagnum moss and on the grass 

 tussocks, and never anywhere but in swamps. 



It has slender, widely-creeping, many-rooted rhizomes, from which rather distant 

 fronds arise. The stipes is long, thin, erect, straw-coloured, or light brown above, 

 and dark at the very bottom, and furnished with a few, scattered, pale brown or yellow 

 scales, which often fall ofF as the frond develops. Rachis straw-coloured below, 

 shading to green above ; also slightly scaly when young. Frond rather broadly 



