Nephrolepis] i. — filices. 65 



free. Sori dorsal, arising from the apex of the upper branch of a 

 vein, generally near the edge. Involucre reniform or rounded. 



1. N. cordifolia, Presi. 



Rhizome almost wanting, emitting long wiry fibres. Stipes stout, 

 wiry, 1-4 in. long, slightly scaly. Fronds tufted, 1-3 ft. long, 1^-2 in. 

 broad, linear-lanceolate, acuminate, rather coriaceous j pinnse ^-1 in. 

 long, close-set, oblong, obtuse, entire or slightly crenate on the 

 margin, the under side rounded or cordate at the base, the upper 

 distinctly auricled. Sori in a single row, half-way between the 

 margin and midrib ; involucre firm, reniform, brown or blackLsh, 

 oblique or opening towards the outer edge. 



Synonyms. — N". tuberosa, Pres^.; N. pectinata, /Sfc/toM ; Aspidium 

 cordifolium, Swartz ; A. tuberosum, Bory, <&c. 



Distribution. — Common in the tropical regions of the New and Old 

 World ; also in N.S. Wales and Queensland. 



This fern is another of those tropical species which apparently were 

 •at one time spread over the northern jjarts of the North Island, but 

 Are now only able to maintain their ground where the hot springs 

 keep up a sort of artificial tropics. It occurs only in two localities 

 in New Zealand — viz., at Otumakokori and at Tapuaeharuru, both in 

 the hot lake district. In the former place it is abundant, but only 

 in such spots as are influenced by the warm water of the river. 



With the shelter of a greenhouse, it may be easily cultivated, 

 requiring abundance of water and good drainage. It is a very 

 •elegant fern. 



In. tropical America and India the fibres of the rhizome bear 

 ■ovoid, scaly tubers, which constitute an article of food. 



Genus XXIIL— POLYPODITJM,* L. (PI. III. figs. 6 and 7, 

 and frontispiece.) 



Rhizome usually creeping, sometimes erect or almost wanting. 

 Fronds simple, pinnate or compound ; venation various. Sori round 

 >or rarely oblong, dorsal, without an involucre. 



The largest genus of ferns, but broken up by many authors into 

 several distinct genera. Thus the ten species recorded below belong 

 — according to Mr. J. Smith's classification — to no less than seven 



(I. Pliegopteris). — Veins free. Fronds 

 2-3-pinnate, with pinnatifid pin- 

 nules ; stipes, rachis and surface 

 with reddish glandular pubescence... 1. P. punctatum. 



* Gr. Polys, many, pous, a, foot, from the numerous branches or stipes of 

 some of the species. 



