21 



by that of its neighbours, as much of its beauty is dependent upon 

 the regular development of the fronds, and the erect vase-like form 

 of them in the mass. 



LASTREA. CRISTATA. Crested Fern. TAB. X. 



Fronds linear-oblong, nearly bipinnate ; pinnae short triangular- 

 oblong, deeply pinnatifid with oblong serrated lobes ; the lower 

 lobes or pinnules often almost pinnatifid. Sori chiefly confined to 

 the upper part of the frond. 



Lastrea cristata, Presl. Aspidium cristatum, Swartz. Smith. 

 Hooker. E. B. Polypodium cristatum, Linneeus. Polypodium 

 Callipteris, Ehrhart. Lophodium Callipteris, Newman, Hist. 

 Brit. Ferns, 169. 



One of our rarest English Ferns, or at least extremely local in 

 its distribution, being confined to boggy heaths and moors, and 

 found hitherto in only four of the counties of England. The re- 

 corded habitats are Westleton, Suffolk; Holt Heath, Fritton, Der- 

 singham, Edgefield, and Bawsey Heath, Norfolk ; Oxton Bogs and 

 Bulwell Marshes, Nottinghamshire; and Wybunbury Bog, Cheshire. 

 The Suffolk station is doubtful. Several years back I searched the 

 locality where Mr. Davy is said to have found it, without success, 

 though guided to the alder bushes where his specimens were col- 

 lected, nor could I meet with the plant anywhere in the neigh- 

 bourhood. According to Mr. Newman, it does not appear to have 

 been found there by any recent examiner. 



It is remarkable that L. Filix-mas should have been frequently 

 confounded with the present species, considering the striking dif- 

 ference in habit that exists between them ; but the desire to add a 

 rarity to his collection will occasionally lead even an accomplished 

 botanist into a similar mistake to that by which we have a Suffolk 

 habitat recorded for a fern that probably does not grow there. 



The rhizoma is stout and strong, and, branching occasionally in 

 different directions, frequently occupies in old plants a considerable 

 space, sending up annually a tuft of erect fronds from the extre- 

 mity of each branch or crown. The fronds attain a height of two 

 feet or more under favourable circumstances, and are peculiarly 

 erect, so as to render it next to impossible for a person who has 

 once seen it growing naturally to confound it with any other native 

 fern. Kather more than one-third of the rachis is bare of pinnae, 

 and more or less covered with scattered broad obtuse pale brown 

 membranaceous scales ; the pinnae, nearly equal in length except 

 toward the apex, are in rather distant and generally opposite pairs ; 

 their segments, often assuming the character of distinct pinnules in 

 the lower part, are deeply serrated, and sometimes even pinnatifid, 



