POLYSTICHUM. CYSTOPTERIS. 423 



curva IV. 225. Frond long, triangular, concave above ; the lower 

 pinnae much the largest. A smaller plant than the two pre- 

 ceding. Sweet-scented. Damp places. P. VIII. IX. 



5. POLYSTICHUM Roth. 



1 . P. Lonchitis (Roth) ; fronds rigid linear simply pinnate, 

 pinnae not lobed serrate spinous their base auricled above oblique 

 below. N. 163. Aspidium Sm., E. E. 797- Stipes very short. 

 Fronds narrow, very rigid and leathery. Pinnae overlapping and 

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

 lower ones usually auricled both above and below. Young and 

 simple pinnate fronds of the next species are often distinguished 

 from this with difficulty. Alpine rocks. P. VII. Holly-fern. 



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

 pinnate, pinnules obliquely decurrent acute. IV. 169. A. lobatum 

 Kunze. A. aculeatum and A. lobatum Sm. Stipes usually short. 

 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 pinnatifid or with one or more 

 pinnules distinct. A few of the lowest pinnules are often slightly 

 stalked, but very differently from those of P. angulare. /3. A. lo- 

 batum (Sm.) ; pinnae less divided than in the type of the species 

 and the fronds linear-lanceolate and more rigid. Hedge-banks. 

 P. VII. VIII. 



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

 pinnate, pinnules truncate below distinctly stalked bluntish. IV. 

 173. Aspidium Sm., E. B. S. 2776. A. aculeatum Kunze. 

 Stipes usually long. First upper pinnule scarcely longer than 

 the others, its lower side rounded 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, similar or rather more deeply serrate 

 than the others ; all short, broad and bluntish ; or first upper pin- 

 nule deeply pinnatifid, all more acute ; or pinnules all narrower 

 and acute. Sheltered woods and hedge-banks, chiefly in the 

 west. P. VII. VIII. 



6. CYSTOPTERIS Eernh. Bladder-fern. 



1. C. fragilis (Bernh.) ; frond lanceolate bipinnate, pinnae 

 ovate or ovate-lanceolate, pinnules oblong-ovate rather narrowed 

 below acute or bluntish pinnatifid or cut serrated. Clusters 

 rarely confluent. Pinnae rather wedgeshaped at their base. 

 "Sporules echinate." a. C. anthriscifolia (Roth); pinnules 



