Asplenium.] XCIV. FILIOES. 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. SCOLOPENDRITTM. HART'S- TONGUE. 



Fronds entire or lobed, with linear diverging son 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. 1305). Hart' s-tongue. 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 1^ 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 5 inches. Son 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 Asplcnvum, 

 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. officinal-urn, 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. Asplenium 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. BLEOHNUM. 



Sori linear, one on each side of the midrib of each segment and 

 parallel to it. Indusium attached along the outer edge of the sorua, 

 opening outwards from the inner side. 



