POLTSTICHITM. CTSTOPTEKIS. 449 



narrow, very rigid and leathery. Pinnse overlapping and 

 twisted (most in the Irish, much less so in the Welsh plant), 

 lower ones usually auricled both above and below. — Young 

 simply pinnate fronds of the next species are often much like 

 this plant. — Alpine rocks. P. VII. Holly Fern. E. S. I. 



2. P. actdedtum (Roth) ; fronds rigid linear or lanceolate bi- 

 pinnate, pinnules obliquely decurrent. — N. 169. S. F. 11. As- 

 pidium lobatum Kunze. A. acideatum and A. lobatum Sm. — 

 Stipe usually short. Frond 1 — 2 feet high. First upper 

 pinnule of each pinna longer than the others, its lower side 

 (next the main rachis) usually nearly straight, its upper acutely 

 auricled and forming an acute angle with the lower and with 

 the partial rachis at the point of attachment. In young plants 

 the pinnae are serrate or pinnatifld or with one or more pin- 

 nules distinct. A few of the lowest pirandes are often slightly 

 stalked, but very differently from those of P. angulare. — A. 

 lobatum (Sw.) has the pinnae less divided than in the type of 

 the species and the fronds linear-lanceolate and more rigid. 

 H. F. 10.— Hedge-banks. P. Vn. Vm. E. &. I. 



3. P. anguldre (Newm.) ; fronds lax drooping lanceolate bi- 

 pinnate, pinnules truncate or obtuse-angled below distinctly stalked. 

 JV. 173. H. F. 12. — Stipe usually long. First upper pinnule 

 scarcely longer than the others, its lower side roimded below, 

 its upper with a large bluntish auricle and forming an obtuse 

 angle with the lower, at the top of the short stalk which is 

 nearly at right angles with the partial rachis ; all short, broad 

 and bluntish ; or first upper pinnule longer and deeply pin- 

 natifld, all more acute ; or pinnules all narrower and acute. — 

 Sheltered woods and hedge-banks, chiefly in the West. P. 



vn. vni. E. s. L 



6. Cystop'teeis Berrih. Bladder-Fern. 



1. C. frag'ilis (Bemh.) ; irond lanceolate bipinnate, pinnae 

 ovate or ovate-lanceolate, pinnules oblong-ovate or cordate- 

 ovate pinnatifld or cut. — a. vera-, usually bipinnate, pinnules 

 rather narrowed below, veins ending at tip of term, teeth or if 

 pinnule emarginate in the 2 teeth not in the notch. Sporules 

 prickly. — a. C. anthriscifolia (Roth) ; pinnules ovate acute cut, 

 segments oblong toothed. Cystea Jragilis Sm., N. 155. — h. C. 

 cynapifolia (Roth) ; pinnules obovate out, segments obovate 

 toothed or retuse at the end. C. fragilis E. B. 1587. — e. C. 

 angustata (Sm.) ; pinnules lanceolate acute cut, segments lan- 

 ceolate-oblong cut, teeth acute. N. 156. — 0. C. dmtata (Sm.) ; 

 frond often only subbipinnate, pinnules broadest below blunt 

 bluntly toothed, veins as in a. 3. F. 23. N. 154. C. fragilis 



