On the British species of Poly podium. 149 



destroyed. I do not pretend to have done this ; but not hav- 

 ing done so, I must resort to the best evidence I can adduce. 

 In the first place, I have collected fronds which will connect 

 angulare with seminalis, passing through all the intermediate 

 varieties. 2ndly, I have found fronds of seminalis, lonchiti- 

 doides, and lobatum, on the same root. 3rdly, I have seen 

 immense roots of aculeatum and lobatum, having had their 

 hold disturbed by plough or spade, actually returning, in their 

 recent fronds, towards the seminalis habit, although still pos- 

 sessing the dried remains of the mature and fully developed 

 fronds, which, under more favorable circumstances, had been 

 produced the previous year. Of the variety lineare I am ig- 

 norant ; I have been led by a figure of the plant, to place it 

 here. 



10. P. fragile. 



I know scarcely anything of the described varieties of this 

 delicate and truly fragile species. It occurs abundantly about 

 the waterfalls, and on moist rocks and walls throughout Wales, 

 throwing up its little bunch of delicate and feathery fronds, 

 from between the clefts of rock, or the interstices of the stone. 



a. fragile. " Frond "between oblong and lance-shaped, twice pinnate; 

 leaflets egg-shaped, pinnatifid, the lobes toothed or serrate, partial 

 stalks bordered ; sori crowded." 



/3. dentatum. " Frond between oblong and lance-shaped, twice pin- 

 nate ; leaflets egg-shaped, obtuse, pinnatifid ; the segments oblong, 

 obtuse and toothed, partial stalks bordered." 



y. angustatum. " Frond oblong ; leaflets lance-shaped, decurrent, pin- 

 natifid, with linear acute segments ; sori scattered, remaining sepa- 

 rate." 



6\ alpinum. "Frond tri-pinnate, ovate-lanceolate; pinnules ovate, 

 blunt, segments linear, obtuse, toothed. 



€ . regium. " It is distinguished from alpinum by its more compact 

 frond, by its shorter, broader, and cuneiform segments, and by the 

 still more important characters of its more copious sori, and of its 

 narrower and tapering indusium. In alpinum the segments are li- 

 near, and the sori much fewer, being mostly solitary on the lobes, 

 and the indusium broader, truncate, and not taper-pointed." D. Don, 

 in Linn. Trans, xvii. p. 437. Mr. Don also informs us that he knows 

 of no British station for P. regium. 



P. regium being thus, for the present, dismissed, I confess 

 I am not sufficient botanist to recognise the other varieties, 

 should I ever be fortunate enough to find them. 



11. P. Ilvense. Frond pinnate, pinna elongate, cordate, pinnatifid, scaly. 

 a. Ilvense. As above. 



£. hyperboreum. Varies in having the pinna shorter, and the frond less 

 scaly. 

 I have seen these plants growing, and should not have no- 

 ticed the difference between them. 



