Cistoptcris. ] 
FERNS. 
23 
lanceolate, pointed, and finely tapering towards the apex. Racliis 
very brittle and shining, of a dark brown or black color on the lower 
part, and quite smooth, except a tuft of scales at the very base. 
Pinnse opposite, pointed, about 20 pairs, confined to the upper half 
of the rachis, and growing nearly at right angles to it. Their length 
more than twice their width, except the lower pair, which are also 
distant from the next above them. Pinnules alternate, acute, 
deeply lobed, crenate or bluntly acute, decurrent and tapering 
more or less at the base. Sori numerous, confluent, black when 
young, afterwards a shining brown, and found throughout the 
summer. Indusium white, with an irregular margin, and soon 
obliterated or thrown off by the growing thecae. 
In general habit resembling the last species, but instantly to be distinguished 
by the shape of the frond, which is sharper and longer pointed, as is also the 
case with the pinna? and pinnules ; the whole is also much more divided, all 
the larger pinnules being cleft, and not merely toothed, as in every state of 
Cistoptcris Dcntata. The stem is also darker, longer, and more brittle, and 
the sori so numerous as soon to become confluent. 
No Ferns are more altered by circumstances than this genus; hence the 
difficulty of distinguishing the species. The varieties, however, arc not distinct 
in themselves, as they may all sometimes be found upon the same plant, 
and different seasons produce differently shaped and divided fronds: for exam- 
ple, those which arise in ordinary seasons alone answer the above description ; 
a cold spring occasions barren fronds, the pinnules of which arc rounded, 
delicate, wide, crenate, and running much into each other ; while long-con- 
tinued drought or warm weather occasions those fronds which arise in summer 
to be much smaller, much yellower, more entire, and the sori more crowded. 
Iu the extreme state it may be described as follows : Frond linear, oblong. 
Pinna; ovate, blunt, pinnate, ovate or round, toothed, quite covered with sori. 
If the summer continue very wet and cold, the fronds do not take the above 
character, but have broader and darker coloured pinnules, in this case exactly 
resembling the cultivated Cistoptcris Dcntata, except in the shape of the frond 
itself. 
Sit. — On alpine rocks, and lofty situations. 
Had. — Eng. : Cumberland, Ruins of Pcveril Castle, Castleton, and the 
Lover’s Leap, near Buxton, Derbys., Mr. H. C. Watson. Cheddar, Somers., 
Mr. W. C. Trevelyan. Matlock, Derbys., Dr. Hoivitt. Near Wrexham, 
Denbighsh., Mr. J. E. Bowman. Near Richmond, Yorks., Mr. J. Ward. 
About Settle, Yorks., Mr. J. Tatham. Nottinghamsh., Mr. T. H. Cooper. 
Near Bristol, Miss Worsley. At Exwick, near Exeter, Mr. Jacob . — Wal. : 
Cave at Clogwyn Coch Snowdon, and rocks above Cwm Idwel, near Twll 
Du, Mr. W. Wilson. — Sco. : Aberdeenshire, Mr. H. C. Watson. Moray and 
Rosshire, Iie.v. G. Gordon. Near Maens, Berwicksh., Rev. A. Baird. Suther- 
land and the Kincardineshire Coast, Dr. Murray. Near Killin, Mr. W. Wilson. 
Ire. : Rocks and mountains of Kerry. Mr. Mackay. Lough Ina, and Lough 
Derryclare, Cunnemara, Mr. Shuttleworth. 
Geo. — Common in Germany, Saxony, Switzerland, Holland, &c. 
