FILICES. 97 



softer in texture, of a brighter and yellower green, more abrirpt at 

 the base, from even the lowest pinnae being elongated so that the 

 frond does not taper insensibly to the base ; the pinnules are smaller 

 in proportion, more distinctly stalked, and with a greater basal angle 

 than those of P. lobatum, and fewer of them towards the apex of the 

 pinnae and towards the apex of the frond are confluent. The indusia 

 are larger and more convex. 



The seedling form of P. angulare apparently never has the close 

 resemblance to adult P. Lonchitis which that of P. lobatum has, for it 

 has an elongated stipes and an abrupt-based frond, with deeply 

 pinnatifid lower pinnae, even though it may be but a couple of inches 

 long. 



P. angulare is much more sensitive to frost than P. lobatum. In 

 Balmuto Garden the former has its fronds always destroyed during 

 the winter; while those of P. lobatum remain green until the new 

 fronds are developed in summer. 



Var. /3, which Wilde considers the Aspidium hastulatum of Ten ore, 

 bears much the same relation to the ordinary form of P. angulare 

 that the var. affinis of Lastrea Filix-mas bears to the var. genuina of 

 that species. 



The var. alatum of Moore shows an approximation to" P. lobatum, 

 var. aculeatum, in having the pinnae running into a narrow 

 herbaceous wing along the rachis ; but in texture, form of frond, and 

 pinnae it agrees with the type of P. angulare. 



Var. gracile, with other forms, called by fern-cultivators lineare, 

 grandidens, confluens and proliferum, are remarkable for their narrow 

 lanceolate incised pinnae, with wedge-shaped bases, not strongly 

 curved on the posterior side, so that in this they also show some 

 approach to P. lobatum, but the forms are usually malformed or 

 monstrous. 



P. angulare is a special favourite with fern-growers, as it produces 

 a great number of curious and abnormal deviations, there being over 

 150 named forms in cultivation. 



It is remarkable that P. Braunii (Aspidium Braunii, Milde, Fil. 

 Europ. p. 108) growing in continental Europe has not occurred in 

 Britain ; it appears to be the only one of the group of plants included 

 in the Polypodium aculeatum of Linnaeus which occurs in Norway 

 and Sweden, and in North America. Mr. Moore considers it as 

 a variety of P. angulare ; but Milde regards it as a subspecies equally 

 distinct from P. angulare (which he calls aculeatum) and from P. 

 lobatum, under which he includes the aculeatum of Smith. In texture 

 and habit it agrees with P. angulare, but the fronds taper insensibly 

 to the base, and have a very short stipes, as in P. lobatum. The 

 pinnae are larger in proportion than P. angulare, and have numerous 

 hair-like scales when young, not only on the lower, but on the upper 

 surface, which is not the case in P. angulare or P. aculeatum ; and 

 the sori are larger than those of P. angulare, and much less numerous. 



VOL. XII. O 



