A HISTORY OF NORFOLK 



it is however still tolerably widely distributed. In the North-Central 

 division the Genus Polystichum is largely represented by a numerous series 

 of forms varying from a Lonchkidoid form of a few inches high, sometimes 

 fairly fruited, to a large sub-tripinnate form of P. atigu/are, of nearly as 

 many feet in length ; in fact, there appears to be an almost unbroken 

 succession of forms from the smallest to the largest, from the most 

 simple to the most divided, and it is difficult to say when P. lobatum ends 

 and P. angulare begins. This series of Polystichum is accompanied by 

 a considerable quantity of Scolopendrium vulgare, which is otherwise a 

 scarce fern throughout the county. 



Asplenium viride has been found on a wall on the extreme southern 

 edge of the Eastern division, and held its own for many years, until 

 exterminated by structural alterations of its habitat. Cystopteris fragilis 

 is known in one or two localities, and Ceterach officinarum in about 

 twice as many. 



Oi Equisetacea, E. maximum, E. syhaticum, and E. hyemale are the least 

 common, and of Lycopods Lycopodium Selago is the rarest, recorded only 

 from the North-Central division ; whilst L. inundatum and L. clavatum 

 have not been recorded from the South-Central. 



Pilularia globulifera has only been found in a very few localities, 

 most of them in the Eastern division. 



FiLICES 



Pteris aquilina, Linn. . 

 Lomaria Spicant, Desv. . 

 Asplenium Adiantum - nigrum 



Linn 



var. acutum. Poll. . 



— viride, Huds. (extinct ?) . 



— Trichomanes, Linn. . 



— Ruta-mutaria, Linn . 

 Athyrium Filix-foemina, Roth 

 Ceterach officinarum, Willd. . 

 Scolopendrium vulgare, Symons 

 Cystopteris fragilis, Bernh. 

 Polystichum lobatum, Presl. 



a. genuinum, Syme. 



b. aculeatura, Syme 



— angulare, Presl. 

 Lastraja Thelypteris, Presl. . 



— Oreopteris, Presl. . 



— Filix-mas, Presl. . 



— cristata, Presl 



— - uliginosa, Newman 



Lastrxa spinulosa, Presl. . 



— dilatata, Presl 



Polypodium vulgare, Linn. . 

 Osmunda regalis, Linn. . 

 Ophioglossum vulgatum, Linn. 

 Botrychium Lunaria, Sw. . 



Equisetace^ 

 Equisetum maximum. Lam. . 



— arvense, Linn 



— sylvaticum, Linn. . 



— palustre, Linn. 



— limosum, Sm 



b. fluviatile (Linn.) 



— hyemale, Linn. 



Lycopodiaceje 

 Lycopodium Selago, Linn. 



— inundatum, Linn. . 



— clavatum, Linn. . 



M 



ARSILEACEJE 



Pilularia globulifera, Linn. . 



CHARACEiE 



The CharaceJB of Norfolk merit special recognition and notice, inas- 

 much as the county stands first in the British Isles for the number 

 of species which it yields. Twenty-five species are recorded for Great 

 Britain ; of these no less than seventeen are found in Norfolk. Nor can 

 it be claimed that this is a complete record. The Characese flora of the 



58 



