146 On the British species of Poly podium. 



7. P. Filix mas. Frond pinnate, pinna nearer, alternate, pinnatifid, 

 lobes obtuse, almost truncate, with serrated margins ; sori discoidal, retain- 

 ing the cover very long. 



The named varieties of this abundant fern are never consi- 

 dered species, except the last. 

 a. Filix mas. As above. 



/3. variegatum. The same, but variegated in colour. 

 y. recurvum. The same, pinnce crisped and turned down. 



d. spinosum. Lobes more serrated. 



e. rigidum. Frond almost bi-pinnate, and having a greater length 

 of rachis without pinnce. 



The name of rigidum has been variously applied by Eng- 

 lish botanists. In herbaria we usually find it represented by 

 one of the varieties of dilatatum ; and more especially by the 

 variety spinulosum of these notes. Others again have attach- 

 ed the name to this variety of Filix mas. And thirdly, a still 

 different plant, said to have been found by Mr. Bree on Ingle- 

 borough, has been called by this name. Supposing the Po- 

 lystichum rigidum of Decandolle &c. a plant found in Swit- 

 zerland, to be really a species, on which I cannot pretend to 

 give an opinion, and supposing it ever to be found in Britain, 

 it will occupy a station between Filix mas and dilatatum. 



The varieties variegatum and spinosum are mentioned sole- 

 ly out of respect to those botanists who have taken the trou- 

 ble to name them ; other varieties are mentioned in the course 

 of this paper, on the same principle. The variety recurvum, 

 is of a different character ; it is constantly and decidedly dis- 

 tinct, whether the frond be large or small, barren or fruitful, 

 seedling or mature ; it grows to a vast size. I found a plant 

 of it in a thick wood, on Dinmore Hill, in Herefordshire, 

 which had six fronds, each exceeding 5 feet in height. Fi- 

 lix mas, in its usual form, also grows to nearly the same size 

 in the same locality. 



8. P. dilatatum. Frond triangular. 



a. murale. (n. v.) Frond pinnatifid, pinnce dentate. 



In this state the plant is much smaller than Asplenium Ru- 

 ta muraria, but in its simply pinnatifid frond, and general 

 habit, it more resembles a dwarf plant of Polypodium vulga- 

 re. It is usually supposed, by intelligent botanists, to be 

 Asplenium Adiantum nigrum. This is the true seedling state 

 of the species ; and may occasionally, though very rarely, be 

 found in the young state, especially in moss. It is found in 

 an old state, with very tufted roots, and a scaly rachis, on old 

 churches and garden walls, in company with Grammitis Ce- 

 terach, Asplenium Trichomanes, A. Ruta muraria, A. Adian- 

 tum nigrum, and Polypodium vulgar e. 



£. riparium. (n. v.) Frond pinnate, pinnce deeply dentate. 



This variety is variable in size, sometimes reaching 4 inch- 



