THE SMOOTH TIIREK-ISRANCHED POLYPODY. 



branches and ihosc of the two basal pinnules of the lower branches, which latter diverge so as to 

 represent two separate angles. The fronds are tomato, that is, they consist of three nearly equal 

 portions or branches, as indicated by the vernation. BroncAe* pinnate or subbipinnate, differing from 

 each other chiefly in this, that while the upper or central one has its sides nearly equal, the two 

 lateral ones have the pinmc on their lower side larger, sometimes twice a* large as those on the upjier 

 side, so that thoy are obliquely triangular. Pinnw opposite, variable in outline from ovate to linear- 

 oblong, acute, usually pinnate at the base, pinnatitid above, and acute as well as nearly entire at the 

 n]H?x ; those of the central branch more decidedly pinnate than those of the lateral ones. Pinnules 

 or tobules oblong-obtuse, eremite or crenato-lobatc, smaller and less divided towards the apex. 



I 'motion of the mora compound, that is the crenato-lobatc pinnules, consisting of a flexuose midvdn 

 with alternate mAw, one to each lobe, these veins pinnato-furcntely branched, the rmui&t extending to 

 the iiiargiu. The veins of the crenate pinnules have fewer branches or venules. The first anterior 

 venule bears a sonis some distance below its termination. 



Fructification on the back of the frond, and spread over its whole surface. Sort small, circular, 

 consisting of numerous crowded spore-cases quite uncovered, arranged in a linear often crowded scries, 

 along each side of the pinnules near to but distinctly within the margin, the sori being seated somo 

 distance below the apex of tho venules. Sometimes the fronds are less abundantly fructified, and the 

 Bori appear distant and scattered. Spore-cases small, dark-brawn, round ish-obovatc, attached by a 

 slender pedicel. Spores ovate, roundish, or oblong, with a granulated surface. 



Duration, The rhizome is perennial. The fronds are annual, produced about April, and in 

 succession through the summer, ami perishing early in autumn. 



The nearest affinity of this species is with P. Itobtrtinnurn, from which some botanists do not think it 

 to differ. It can, however, hardly be supposed that those who have seen tolerably good examples of l>oth 

 would hesitate to admit their distinctness, I\ Dryoptcris differs from P. Uobcrtianum in having a loosely 

 spreading habit, while the fronds of the latter are rigid and erect, with stouter stalks and ribs, and a 

 less membranaceous texture ; it differs further in having tomato or three-branched fronds, which is not 

 strictly the case with the latter, although by a misapplication of terms it is sometimes so described. 

 P. Dryopteris is decidedly three-branched, as its vernation, compared to three little balls on slender 

 wires, certifies ; whilst in P- Robertianum, as Mr, Newman well states, the three corresponding portions 

 of the fraud never assume this appearance, but, on the contrary, every pinnule is railed up into a little 

 globe, the pinna? rolled in on the includes, and the entire frond upon its rachis, so that the frond is of the 

 ordinary bipinnate structure. Of less botanical importance perhaps, but equally, or still mora clearly 

 available as distinguishing characteristics, are, the perfect smoothness of P. DryopUris, compared with 

 the glandular pubescence of P. Rcbertianum, most readily seen on the stipes and rachis, but equally 

 occurring over the whole plant These peculiarities, which are perfectly constant in a state of cultivation, 

 mark (he plants as abundantly distinct* 



Most writers describe a cruciform figure as Wing formed by the basal pinnules of the opposite sessile 

 pinn& in P. Dryoptcri* ; and it is sometimes figured, as in Mr. Newman's work, in a very marked 

 manner. Some approach to this arrangement is Indeed at times observable, but in numerous suites of 

 specimens we have never seen it in any marked degree ; and when it does occur, two of the four 

 pinnules (the upper pair) ara smaller, and nearly parallel, while the lower and larger ones are 

 divergent. 



This species is a moisture-loving plant, although, as in most other instances, the moisture must not 

 be stagnant It is also peculiarly a shade-loving Fern ; for, though very hardy, and capable of 

 existing under considerable exposure, yet tho delicate fronds arc damaged and disfigured unless both 

 shade and shelter of some kind is afforded it. It is a good plant for a shady out-door rockery, and also 

 grows readily in ]>ots. It increases with facility by division of the rhizome. 



V<i 



