Asplenvum.] XCIV. FILICES, 567 
part of Europe and central and Russian Asia, from Spain to Scandinavia, 
and in the mountains of North America. In Britain, in several of the 
western and northern counties of England and in Scotland, but not in 
Ireland, Fr. summer and autumn, 
IX. SCOLOPENDRIUM. HART’S-TONGUE. 
Fronds entire or lobed, with linear diverging sori as in Asplenium, 
but the indusium is attached along both sides, opening in 2 valves by 
a longitudinal fissure along the centre. 
The few species associated with our British one are from the tropics 
or the Mediterranean region. 
1. S. vulgare, Sm. (fig. 1805). Hart’s-tongwe.—Fronds tufted, un- 
divided (except in monstrous forms), broadly linear or narrow-oblong, 
cordate at the base, with rounded auricles, usually about a foot long 
and 14 to 2 inches in the broadest part, of a firm consistence, smooth 
and shining on the upper surface, with a brown or greenish foot-stalk 
of about 2 to 4 or 5inches. Sori numerous, transverse and parallel, in 
2 rows, one on each side of the midrib, usually of very different lengths, 
but never reaching either to the midrib or to the edge of the frond. 
On shady banks, rocks and walls, in ravines, &c., in temperate and 
southern Europe, west central Asia, Japan, and north-west America, ex- 
tending from the Mediterranean to the Baltic. Common in Britain. 
Fr. the whole season. It varies much in size from 6 inches to near 2 feet, 
and in the fantastic forms assumed by the barren fronds when monstrous, 
especially under cultivation. No less than 58 of these forms are named 
in Moore’s Handbook. 
—— 
X. CETERACH. CETERACH. 
Fronds pinnatifid or pinnate. Sori linear and diverging as in Asplenium, 
but without any distinct indusium, and usually almost concealed under 
the scales of the under surface of the frond. 
The genus is now limited to the European species and a second larger 
one from the Canary Islands. 
1. C. officinarum, Desv. (fig. 1306). Ceterach.—Fronds tufted, spread- 
ing, about 2 to 6 inches long, deeply pinnatifid or pinnate, with broadly 
oblong or rounded lobes or segments attached by their broad base, green 
and glabrous on the upper side, but the under side thickly covered with 
brown scarious scales, which completely conceal the sori until they 
become very old. Aspleniwm Ceterach, Linn. 
On rocks and old walls, in central and southern Europe and west 
central Asia, extending northward to Holland. In Britain, common in 
many parts of England, especially western, and in Ireland and western 
Scotland. fr. summer and autumn. 
XI. BLECHNUM. BLECHNUM. 
Sori linear, one on each side of the midrib of each segment and 
parallel to it. Indusium attached along the outer edge of the sorus, 
opening outwards from the inner side. 
