Ai,LOSORUS. POLYPODIUM. 419 



Tr. VI. OSMUNDEJE. 



,18. OSMUNDA. Capsules clustered, arranged in a branched 

 spike terminating the frond. 



Suborder IV. OPHIOGLOSSACE.E. 



Vernation straight. Rachis succulent. Capsules regularly 

 2-valved, sessile, in clusters on a separate branch of the frond. 



Tr. VII. OPHIOGLOSSE^. 



19. BOTRYCHIUM. Capsules distinct, disposed in a com- 

 pound spike attached to a pinnate or bipinnate frond. 



20. OPHIOGLOSSUM. Capsules connate, disposed in a simple 

 distichous spike attached to an undivided frond. 



Suborder I. Polypodiacece. Tribe I. Polypodiece. 

 I. ALLOSORUS Bernh. Rock-brake. 



1. A. crispus (Bernh.) ; barren fronds 2 3-pinnate, leaflets 

 wedgeshaped or linear-oblong often bifid at the end, leaflets of 

 the fertile fronds oblong. N. 103. Pteris Sm., E. B. 1160. 

 Cryptogramma R. Br., Hook. Fertile frond nearly triangular. 

 Veins alternate, often forked and each branch ending in a cluster 

 having no indusium but concealed by the reflexed edge of the 

 leaflet. Height 6 12 in. St. slender, very brittle. - Stony 

 places on mountains. P. VII. 



2. POLYPODIUM Linn. Polypody. 



* Clusters at the end of a veinlet, other veinlets knobbed at the 

 end and not reaching the edge. CTENOPTERIS Newm. 



1. P. vulgare (L.) ; fronds deeply pinnatifid, lobes linear-ob- 

 long somewhat serrate all parallel upper ones gradually smaller. 

 E. B. 1149. N. 111. Rhizome brown, densely scaly, creep- 

 ing. Fronds strapshaped. Clusters large, on the upper part of 

 the frond. Lateral veins of the pinnae with 4 branches. Pinnse 

 occasionally bifid at the end, sometimes deeply serrate or even 

 (P. cambricum L.) doubly pinnatifid. Shady banks, walls and 

 old trees. P. VIII. X. Common Polypody. 



** Veinlets not knobbed but reaching the edge, all usually fertile, 

 clusters near the end of each. GYMNOCARPIUM Newm. 



2. P. ? Phegopteris (L.) ; fronds pinnate, pinnae linear-lance^ 



