Poly podium .] 
FERNS. 
27 
Hab.-Eng. : Rocks at the foot of the Cheviot, above Langley Ford, Mr. 
Winch. Wooded banks of the White Adder, between the Retreat and Elm 
Cottage, Berwickshire, Dr. Johnston. Durham, Mr. R. B. Bowman. Near 
Yoxhall Lodge, in Needwood Forest, Staffordsh., Mr. C. C. Babington. Cum- 
beiland, up to 500 yards of elevation, Mr. H. C. Watson. Higher part of the 
Tees, Mr. J. Hogg. Egerton Moor, near Bolton, Mr. IV. Christy. Dean Church, 
Clough, near Bolton, Mr. J. Martin. Dry places near Lancashire (sparingly), 
at Hill Cliff, Cheshire, and at Warrington, Mr. Rylands. Boghart Hole Clough, 
and Prestwich Clough, Lane., Mr. Merrick. Rocks at the Belle Hag, Sheffield, 
Froddesley Hill, Salop, Rev. IF. Corbett. N. side of Titterstone Clee 
Ilill, Salop, Mr. E. Lees. Near Richmond, Yorks. Mr. J. Ward. Near Bristol, 
Miss Worsley. — Whales : Craig Breidden, Montgomerysh., Mr. J. E. Bowman. 
Rhaiaclr-y-W enol-Twll Du, Caemarvonsh., Mr. C. C. Babington. Frequent in 
N. Wales, and observed near Twll Du at an elevation of 1000 feet and upwards, 
Mr. W. Wilson. Just leaving Llangollen, on a slate rock, Mr. W. Wilson and 
Mr. Bowman. Scot. : Moray, Rossh., Rev. G. Gordon. Perthshire, Forfarshire, 
Aberdeenshire, Mr . H. C. Watson. Hawthorn Dean, near Edinburgh, Mr. T. 
II. Cooper. Ire. : On the mountains of Mourne, Turk Mountain, Killarney, 
Mam-turk, Connamara, Tullamore Park, &c., Mr. Mackay. 
Geo.— Throughout great part of Europe and North Asia. 
4.— POLYPODIUM CALCAREUM. 
RIGID THREE-BRANCHED POLYPODY. LIME POLYPODY. 
smith’s FERN. 
(Suppl. Plate, fig. 1.) 
Ciia. — Leaf-stalk three-branched above, the pair of lateral 
branches pinnate with pinnatifid leaflets, the middle branch bi- 
pinnate, the pinnules more and more confluent upwards, rigid. 
Branches upright. Pinnules obtuse, deeply crenate. 
Syn. — Polypodium calcareum, Swz., Willd., Smith, Hook., Part., Galp . — 
Polypodium Dryopteris, Bolt., Dicks. — Polvpodium Dryopteris (3, With., 
2d edit. — Polypodium Robertianum, Iloffm. — Neplirodium Dryopteris, 
Michx. — Gymnocarpium Robertianum, Netvm., 1854. 
Fig.— E. B. 1525 .—Bolt. 1 .—Ger. 1135. 
Des. — This is so similar to the last, that when dried they are 
scarcely to be distinguished ; hence the doubt of their claim as 
distinct species : but when growing, the eye will instantly see the 
difference between the two. The P. calcareum is known from its 
rootstock being thicker and less creeping, its leaves rather larger in 
size, much more rigid, quite upright, and of a dark green colour ; 
its pinnules more deeply cut, and stalk more scaly towards the base, 
and on the upper part sprinkled over with fine white minute glan- 
dular hairs ; its sori are browner and more numerous. The minute 
pubescence seen on this species is most observable on luxuriant and 
fresh plants. It is, I believe, a constant and decided character, in 
which opinion I am supported by Mr. Wilson and Mr. Babington, 
than whom few are better able to form a correct judgment. The latter 
gentleman observes, that the microscope shows every particle of this 
pubescence or mealiness to be a minute stalked gland {vide Plate). 
