THE COMMON 1 POLYPODY. 



Itttizomc creeping, tortuous, branched, as thick as a swan's quill or one's little finger, densely 

 clothed with ferruginous scales on a deciduous cuticle, and bearing libres on the under side, Scales 

 lanceolate, very much acuminated, crowded, at length deciduous, leaving the surface of the rhizome 

 smooth and greenish. Fibres brawn, tomentose, densely matted over tho surface to which the 

 rhizome is fixed. 



Stipes variable, often nearly or quite as long as the frond, sometimes much shorter, as well as the 

 mcltis slightly grooved in front, naked, at the base articulate*! with the rhizome. 

 Vernation circinato. 



Frond from two to eighteen inches long, lateral to tho rhizome, subcoriaceous, of a somewhat sombre 

 green, paler beneath ; varying in outline from triangular-ovate when small, to ovate-oblong and linear- 

 oblong, the latter being the fully developed condition of the species in its normal state ; very deeply 

 pinnatilid, usually more or less drooping. Lobes or xeytnente liucar-oblong, jmrallel, fiat, bluntish or 

 Abruptly acute, obscurely serrate, more distant and sometimes deflexed, rarely shorter at tho base, shorter 

 and more crowded or confluent near the apex, which sometimes terminates abruptly, but is usuallv 

 caudate. 



Venation in each lubo consisting of a prominent tortuous midvein, which is alternately branched ; 

 the branches (veins) are again branched, producing from three to five alternate branchlcts (venule*), of 

 which the lowest anterior one (rarely more) bears a sorus at its club-shaped n|>ex ; the others are Sterile* 

 and each terminates within the margin in a small transparent club-shaped head. 



Fructification on the back of the frond, usually confined to its upper part* the sorus Originating at the 

 npex of the veinlet; at first a naked depressed scarcely visible spot, and from tho earliest period at 

 which it becomes visible quite destitute of any membranous cover, or indusium. Son or clusters of 

 Apore-cases circular, rarely somewhat oblong, quite exposed, arranged in a linear series on each side the 

 midvein ; at first distinct* often crowded and finally confluent. Spore-cases yellow or orange of various 

 shades, becoming tawny, numerous, globose, with a slender stalk of elongated cells. Spares yellow, 

 murieulatc or corrugate, oblong or kidney-shaped. 



/Juration. The rhizome is perennial. The fronds are produced about the end of Slav, and are 

 Insistent through tho winter and until after new fronds are produced, so that the plant is evergreen 

 unless tho fronds are destroyed or damaged by severe frosL Other fronds are produced later m tho 

 summer. 



This common plant is the typo of the Linmcan genus Potypodhm. There are eertainlv no grounds 

 other than the fancies of name-makers by reason of which that genus should be abolished, although 

 there inay be reasons for its reduction by divesting it of ill-assorted species. We cannot therefore 

 concur with those writers who, adopting tho name used for sectional distinction by Ulume and Presl, 

 would call this plant Ctenoptcris vulgaris and thus altogether ignore Liumeus's Polj/poilinnu What- 

 ever additional names the introduction of modern systems of classification may render necessary, it as 

 clearly not permissible that the names of type species of bond Jhie established gencra> where these can 

 be recognised, as in this case, should l>c wantonly remodelled. Those who are easily led either to make 

 or to adopt changes of this nature, should remember that names are not the ultimate objects of 

 botanical investigation, 



The Common Polypody differs essentially from all the other British Polypodies, in the character of 

 having its fronds articulated with the rhizome — that is, attached in such a manner that they separate 

 spontaneously as they approach decay. Its texture, too, is stouter and tinner than that of the native 

 species which arc allied to it by their fructification. In its normal form, it is, moreover, less divided than 

 they. The small specimens produced on walls, and in other dry exposed places, are erect and rigid ■ 

 but in situations where it grows with more vigour, tho plant becomes drooping ami picturcsm 

 character. 



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