566 THE FERN FAMILY. ) [ Blechnum. ; 
over Europe, extending from the Mediterranean far into Scandinavia, and 
occurs in North-east Asia and North-west America. Common in Britain. 
Fr. summer, rather late, and autumn. 
XII. PTERIS. PTERIS. 
Fronds usually stiff, often large, lobed, or pinnately divided. Veins of 
the segments branching from a midrib. Sori linear, close along the 
margin of the frond, with an indusium attached along its outer edge to 
the margin of the frond, and opening on the inner side. 
A large genus, widely distributed over the globe, and if not very natural, 
at any rate easily recognized. 
1. P. aquilina, Linn. (fig. 1303). Brake Pleris, Brakes, Bracken.— 
A tall, erect, stiff Fern, with a thick, hard, creeping rootstock. Fronds 
1 to 2 feet high in poor soils, 8 to 10 feet high when luxuriant, twice or 
thrice pinnate; the primary pinnas in pairs at some distance from each 
other ; the lowest pair much larger, the others decreasing in size and suc- 
cessively developed, giving the whole frond, especially when young or small, 
a broadly triangular outline. Secondary pinnas numerous, linear-lanceolate, 
deeply pinnatifid or pinnate, always ending in an undivided, crenate, blunt 
point. Segments ovate or oblong, obtuse and entire, attached by their 
broad base, of a firm consistence, glabrous above, often hairy underneath. 
Sori in continuous lines along the margins of the upper segments and sum- 
mits of the secondary pinnas. 
In woods and thickets, on heaths and waste places, dry or moist, but not 
swampy, in almost every part of the globe, except the extreme north and 
south. Very abundant in Britain. Fr. autumn. 
XIII. ADIANTUM. ADIANT. 
Fronds usually delicate and divided, the segments more or less wedge- 
shaped, with diverging forked veins, usually without a midrib. Sori oblong 
or linear, transverse, at the ends of the lobes on the under side, with an 
indusium formed from the edge of the frond and opening inwards, 
A considerable and well-marked. genus, chiefly tropical. 
1. A. Capillus-Veneris, Linn. (fig. 1304). Maidenhair Adiant, _ 
Maidenhair.—A very delicate tufted Fern. Fronds 6 inches to near a foot 
long, twice or thrice pinnate, usually broadly ovate in general outline, 
their slender stalk of a shining brownish-black. Segments obovate or fan- 
shaped, 4: to 8 lines broad, all narrowed at the base into a short, slender 
stalk, more or less divided into wedge-shaped, obtuse lobes, thin, and of a 
bright green, without any midrib, but numerous forked veins converging at 
the base. Sori conspicuous, occupying the extremities of most of the lobes 
of the segments. 
In the fissures of moist rocks, at the entrance of caves and wells, and 
other situations sheltered from cold, as well as from sun and drought, in 
most of the tropical and warmer parts of the globe, common in southern 
Europe, extending northward over the greater part of France, but scarcely 
into Germany. In Britain, only in the southern and western counties of 
England, in South Wales, the Isle of Man, and Ireland. Fr. all summer. 
eax’, 
