THE ALPINE POLYPODY. 



scaly above. Scales numerous, broadly or narrowly ovato-hmccolatc, pale-brown, Fibres stout, 

 branched. 



Stipes short, from about one-sixth to one-fourth of the entire length of the frond, stoutish, swollen 

 near the base, clothed sparingly with ovate-lanceolate pale-brown scales ; terminal and adherent to the 

 caudex. liachis stout, rounded behind, channelled in front ; the rachis of the pinme furnished with a 

 very narrow leafy wing on both sides, connecting the pinnules. 



Vernation circiuatc. 



Frond from one to three feet and upwards in height, erect or ascending, herbaceous, dark dull green, 

 lanceolate, the base narrowed in about the same degree as the point; biphmate, or subtripimmte. In 

 fronds, of which the leafy portion measures about twenty inches in length, the greatest breadth is about 

 six and a half inches. Pimuc broadly linear or lanceolate from a broad base, tapering to a narrow 

 point, numerous, crowded above, more distant below, spreading or somewhat ascending. Pinnules 

 ovate-oblong, sometimes ovato-lanceolate, or oblong-ovate, acute, with a narrow attachment at the base, 

 but connected by a narrow membranous wing which borders tho rachis ; they arc deeply phinatifid, 

 and in the most vigorous fronds so much so, and the segments so far distant from each other, as to 

 api>ear again pinnate, Segments oblong obtuse, sharply serrate, especially at the apex and on the 

 anterior margin. The subtripinnatc fronds have the segments doubly toothed. 



Viwdion of the pinnules consisting of a slightly llexuosc midvcin from which branch a series of 

 alternate pinnate veins. Veins of the segments also llexuosc, with simple alternate venukw, one of which 

 is directed to the point of each marginal tooth ; the lowest anterior venule, which is directed towards 

 the lowest anterior tooth, is usually soriferous, and when this only is so, the sori form a scries on each 

 side the midvcin, at a short distance from it, and just above the sinus of the segments on their anterior 

 margin ; sometimes, however, some of the other venules are also fertile, and the sori arc then placed 

 near the margin of the segments. In the subtripinnatc fronds, which have the segments more or less 

 doubly toothed, the venules arc occasionally forked, the anterior vcinlol, or sometimes both, bearing a 

 sorus ; in these examples the sori, throe or four on each side the segment, form tolerably distinct sub- 

 marginal lines. The son are in all cases attached near to, but below, the apex of tho vein, which 

 reaches* to the margin. 



Fructification on the back of the frond, occupying the upper two-thirds of its length. Swi small, 

 circular, usually distinct, but sometimes crowded, and becoming confluent ; usually naked, but some- 

 times (rarely and in abnormal-looking sori) the spore-cases aro somewhat lateral, and a membrane, 

 which appears to be an abnormal development of the rcccptacular expansion of the vein, is produced, 

 simulating an abortive or spurious indusium. Bpore-etttee roundish-obovate, brown, numerous. Spores 

 roundish or oblong, somewhat muriculato. 



Duration. The caudex is perennial. The fronds arc annual, growing up in April or May, and 

 perishing early in autumn. 



The Pom is at once distinguished among the Kritish Polyjtodics by its short thick erect tufted 

 caudex, and by the lanceolate form, aud biphmate or tripinnate mode of division of its fronds. It has 

 certainly a general resemblance to Athyrium Filix-fwmina, with which it appears to have been very 

 generally confounded, but the fructification, as usually borne, is very different and even its resemblance 

 to that species is not found to be so close as at first sight appears to be the ease. 



The short massive caudex with terminal adherent fronds, would lead those botanists who derive 

 generic distinctions from tho mode of development, to separate the present species from Pvlypodium. 

 It docs in fact represent one of the three new genera in which Mr. Newman lias disposed the five 

 Polypodies which inhabit Great Britain. 



The supposed 'indusia/ ascribed to this plant, we have noticed both in living plants of the species, 

 and in dried specimens of the variety flexile, but they are only occasional, and even rare, and appear 



H 



t*fc* 



