152 BRITISH FERNS. — SUB-ORDER II, TRIBE II. 
from a branch as they approach decay, is a unique character. The 
fronds vary from 2 to 22 inches in length ; are linear, oblong in 
form ; deeply pinnatifid ; with large, conspicuous sori. Except in 
very hard winters, the fronds remain green till spring, when they 
are cast, and fresh ones appear. It grows on rocks, walls, tree- 
stumps, and banks, and is common throughout Great Britain and 
Ireland, from the level of the sea to a height of more than 3,000 
feet. It is also abundant throughout Europe, Siberia, Kamtschatka, 
Canada, the United States, California, Mexico, and Guatemala. 
The sections including Cambricum and semilacerum are not un- 
common in Monmouth and Wales. 
Readily cultivated if grown in leaf mould, sand, fibrous loam, 
and lumps of decaying wood, care being taken that the rhizomes 
shall be fastened on the surface of the soil. In the varieties of 
this fern the departure from the normal form is unusually great. 
Varieties. 
These have been grouped in several sections, Section 8 contain- 
ing all those that could not be classed in Sections a to y. 
Section a. plumosum. 
„ / 3 . cristatum. 
„ y. semilacerum. 
„ 8. anomalum. 
Section n. contains feathery varieties, such as Cambricum, Cornu- 
biense, and pulcherrimum. 
Section fi, the tasselled, branched, or capitate forms. 
Section y, semilacerum and omnilacerum, i.e., lacerate forms. 
Section 8, anomalum (a term used to denote that these are not 
classed). This section contains those varieties not included in 
the first three classes. 
Section a. PLUMOSUM. 
1. Barrowi, Lowe (Cambricum Barrowi, Barnes). Found in 1874, 
at Witherslack, in the Lake district, by Mr. T. Barrow. It is a 
splendid form ; with very dense, finely-cut, thin-textured fronds. 
2. Cambricum, Linnceus (plumosum, Wollaston). A well-known, 
plumose, sterile variety. Found many years ago in Wales. Men- 
tioned as early as 1743. The hate Mr. Joseph Sidebotham, of 
Manchester, found it in North Wales, at Mill Dingle, Beaumaris, 
and Conway Castle; also at Troutbeck, near Ambleside ; and at 
Flenarim, in County Antrim (the Irish form not sterile). Found 
in South Devon, in 1867, by W. Easterbrook. It is also recorded 
from Monmouthshire, Glamorganshire, Cheshire (where it was 
found in a wood near Macclesfield), and from Almondsbury, near 
Bristol. 
3. Claphami, Lowe (multifido-elegantissimum, Clapham). A 
cross between a crested form and “ Cornubiense,” raised by the 
late Mr. Clapham ; in fact, a crested Cornubiense, 
