GYMNOCAEPIUM EOBERTIANUM. 65 



description in the 'English Flora' is in these words : — " Frond 

 three-hranched ; branches doubly pinnate, erect, rather rigid ; 

 segments obtuse, somewhat crenate. Masses of capsules 

 crowded, finally confluent. * * * Boot creeping, but 

 stouter and less extended than in the preceding species (P. 

 Dryopteris). Frond more firm and rigid : its stalk more scaly 

 about the lower part. All the three branches upright, smaller 

 than the last, rigid, and not loosely spreading. Masses of cap- 

 sules more crowded, finally in some degree confluent, and of a 

 browner hue." Our British authors, Hooker and Babington, 

 admit it as a species ; the latter gives the following description, 

 which, it may be observed, comprises diagnostics of more value 

 than any pointed out by Bolton or Smith, although so admira- 

 bly given by Hoffmann. "Fronds subternate, glandular -mealy, 

 lower branches pinnate ; pinnte pinnatifid, obtuse, the upper- 

 most nearly entire ; sori marginal. Very different in habit 

 from the preceding (P. Dryopteris), and always covered with 

 very minute stalked glands, giving a mealy character to the sur- 

 face. Frond not so decidedly trifid, the lower branches being 

 much smaller in proportion to the middle one ; all the three 

 erect, rigid." Mr. Wilson, whose authority in British ferns is 

 certainly inferior to no one's, also considers the present species 

 distinct from G. Dryopteris, " I consider these plants," says 

 Mr. Wilson, "to be quite distinct, the former [G. Robertianum] 

 having truly the erect habit which Smith describes ; I believe 

 also that the pubescence is constantly present in P. calcareum. 

 The two species are generally found in different habitats, but 

 in a wood on the side of Ingleborough, as you go to Weather- 

 cote, they are found in company. I have cultivated them side 

 by side for many years, with their respective characters un- 

 changed." Mrs. Riley, of Papplewick, near Nottingham, has 

 written a few lines on the same subject, which I shall take the 

 liberty of quoting. " The pubescence, which is one distin- 

 guishing character of P. calcareum, is a beautiful microscopic 

 object, each slender stem supporting a globular head, but this 

 pubescence soon dries, so that only on freshly gathered speci- 

 mens can it be fully perceived or accurately examined. Though 

 we found P. Dryopteris frequently in Wales, we never met with 

 P. calcareum there ; and although, like Mr. Wilson, we have 

 cultivated them side by side for years, we can also testify that 



