BOTANY 



the number of species of lichens and Uredineje has been doubled since 

 the publication of the lists of cryptogamic plants, compiled by Mr. B. 

 Daydon Jackson, which appeared in Pryor's F/ora, for these two groups 

 the greater part of the county is altogether unexplored. On the other 

 hand it is not likely that the Pteridophytes will be added to, nor that 

 any great accession will be made to the Bryophytes. 



THE FERNS (Filices) 



While man has in past times altered the scenery and flora of the 

 county by clearing the forests and draining the land, perhaps one of the 

 greatest pleasures of a stroll along our country lanes has been lost to us 

 during the present generation by the almost total eradication of the 

 ferns which were fairly plentiful and of varied species in our younger 

 days. Some years ago they were uprooted and taken to London from 

 the woods and lanes of southern Hertfordshire in cartloads, but they are 

 now so scarce that this depredation has ceased to be profitable. There 

 is a lane near St. Albans in which not many years ago some half-dozen 

 species were flourishing, but the bracken is the only one now to be 

 found there. This is not due to the rapacity of botanical collectors, but 

 to the wholesale removal of our ferns for the London market, thence to 

 be planted in London gardens, carry on a sickly existence for a few years 

 or maybe only a few months, wither and die. 



Neither in its soil nor in its climate, however, is Hertfordshire a 

 county in which ferns would naturally flourish, both the soil and the air 

 being too dry for them, and the rainfall insufficient and too intermittent. 



Not a single species is recorded from every one of our botanical 

 districts, there being no record in the Cam district even for the very 

 common bracken (Pteris aquilina)^ which indeed is of very rare occur- 

 rence on the Chalk downs. The hart's-tongue (Scolopendrium vu/gare) 

 and the common polypody (Polypodium vu/gare) are the only other ferns 

 recorded for every district but the Cam, in which we have alone on 

 record the male-fern (Lastrea jilix-mas) and the adder's-tongue (Opbio- 

 glossum vulgatum) ; and in the Thame and the Brent the only recorded 

 occurrences are of the three commoner ferns first named. 



Our rarest species are Pilularia globulifera^ found in a pond at Nor- 

 thaw in the Lea district, Lastrea spinulosa and L. oreopteris, recorded only 

 for the Colne and Lea districts, and Ceterach officinarum, which, although 

 rarer than those two, has occurred in the Ivel district as well as in the 

 Colne and Lea. A single specimen of Cystopte ris fragilis has been found 

 in Berry Grove Wood, Aldenham, and a single specimen of Phegopteris 

 calcarea at Broxbournebury, but we cannot consider these to be native 

 ferns. They must have been casuals or escapes. 



The following is a list of the Hertfordshire ferns 



POLYPODIACE^ Scolopendrium vulgare, Sm. 



Pteris aquilina, L. Asplenium ruta-muraria, L. 



Blechnum spicant, Roth trichomanes, L. 



Ceterach officinarum, Willd. adiantum-nigrum, L. 



61 



