44 BRITISH FERNS. — SUB-ORDER II. TRIBE 8. 
Mr. P. Neill Fraser gathered it near Edinburgh. Mr. D. Hutch- 
ison says it is also plentiful near Airlie Castle. Not an Irish 
species. 
Found in the Gulf of Finland, in Norway, Sweden, Belgium, 
Switzerland, France, Germany, Hungary, Spain, Italy, Croatia, 
Dalmatia, Bukowina, and on the Tyrol and Carpathian mountains. 
One variety has been described, — acutidentatum, Moore , which 
was raised from spores by Mr. Sim, of Foot’s Cray. It differs in 
having the teeth of the lobes acute instead of obtuse. 
THE WALL RUE. 
Asplenium Ruta-muraria. — Linnoeus. 
One of our most abundant ferns, though 
less common on the eastern side of Eng- 
land. Found on old walls, rocks, churches, 
bridges, and ruins ; in the drier districts 
occupying a northern aspect. 
Forming tufts of fronds from I to 6 
inches in length, usually about 2 inches. 
It can only be confused with the Asple- 
nium Germanicum, and even this may 
possibly be a hybrid between the Wall 
Rue and the Forked Spleenwort. Al- 
though so common, it is difficult to culti- 
vate. A very large amount of broken 
limestone in proportion to the soil, and a 
dry airy situation is essential. Widely 
spread in all temperate climates. 
Varieties. 
Large growing (5 or 6 inches), branched 
and attenuated. Found at Athlone by Mr. F. J. Foot, of the Irish 
Survey. 
2. cristatum, Wollaston. Tasseled in various ways, and the 
rachis often divided. Found near Ruthin Castle by Mr. J. Daniels ; 
Guildford, by Dr. Allchin ; and near Tunbridge Wells, by Mr. G. B. 
Wollaston. 
3. cuneatum, Moore. Mostly merely pinnate with long, narrow, 
cuneate-based pinnules. Found at Stenton Rock, near Dunkeld ; 
also near Bitton, by the late Rev. T. Ellacombe, of Bitton Rectory, 
near Bristol ; and at Sizergh, in the Lake district, by Mr. J. Cross- 
field. 
4. dissectum, Wollaston. Elongated and deeply incised pin- 
nules. Found in Devonshire by Mr. G. B. Wollaston ; and in 
County Louth by the late Dr. Kinahan. 
5. elatum, Lung. Tall (4^ inches), slender, often tripinnate, 
pinnules very small and narrowly cuneate. Found at Ennis by 
Dr. Allchin; Michelstown Castle, by Mr. P. F. Keir; near Athenny, 
by Mr. R. Barrington ; Keswick, by Miss Wright ; in Dovedale, by 
Mr. Wilson ; and in County Clare, by Mr. O’Kelly. 
Fig. 16. — Asplenium Ruta- 
muraria, var. ramosum. 
1. attenuatum, Lowe. 
