568 : THE FERN FAMILY. 
A small genus, spread over many parts of the world, but chiefly 
tropical. 
L B. Spicant, Roth. (fig. 1807). Blechnum.—Fronds simply pinnate, 
tufted, of two kinds, the outer barren ones spreading, usually 6 inches 
to near a foot long; the segments lanceolate, curved, entire, attached 
by their broad base ; those in the centre of the frond 1 to 14 inches 
long, gradually decreasing towards each end. Fruiting fronds in the 
centre of the tuft, erect, 1 to 14 feet high; the segments of the same 
length as in the barren ones, but all narrow-linear ; the under side entirely 
occupied by the 2 linear sori. B. boreale, Sw. Lomaria spicant, Desv. 
In woods, and rather moist stony places and heaths, generally dis- 
tributed over Europe, extending from the Mediterranean far into 
Scandinavia, and occurs in north-east Asia and north-west America. 
Common in Britain, /7r. summer, rather late, and autumn. 
XII. PTERIS. PTERIS. 
Fronds usually stiff, often large, lobed, or pinnately divided. Veins 
of the segments branching from the 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 recognised. 
1. P. aquilina, Linn. (fig. 1308). 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 successively developed, 
giving the whole frond, especially when young or small, a broadly tri- 
angular 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 
summits 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. 7. autumn. 
. ee 
XIII. ADIANTUM. MAIDENHAIR. 
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 in- 
wards, 
A considerable and well-marked genus, chiefly tropical. 
1. A. Capillus-Veneris, Linn. (fig. 1309). 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 — 
