142 ENGLISH BOTANY. 



linear, usually equidistant from the midrib and the margin of the 

 frond ; the two portions of the compound sorus wholly coalescent. 

 Spores muricated, with numerous prominent acute tubercles. 



On rocks and hedgebanks, and in woods, frequent and generally 

 distributed in lowland districts, more rare in Scotland, but extending 

 to Orkney and Shetland. Frequent in Ireland. 



England, Scotland, Ireland. Perennial. Summer, Autumn. 



Yery variable in size and in the length of the lamina, generally 

 speaking the larger the lamina the longer in proportion is the stipes. 

 Of the lamina I have specimens from 4 inches long by \ inch wide ; 

 10 inches long by 3 inches wide; 17 inches long by 3i inches wide ; 

 and 2 feet long by 2 \ inches wide. These dimensions will show 

 that there is a great want of regularity in the length and breadth of 

 the fronds. Frequently the fronds are more or less undulated and 

 sometimes crisped at the margins, but the latter seldom occurs 

 without the sori being more or less abnormal, often short, sometimes 

 few in number or even absent altogether. 



This is one of the Ferns which are the special delight of fern-growers, 

 from the number of remarkable monstrosities which occur. Some- 

 times the stipes is branched, sometimes the frond is divided into two 

 or more divisions towards the base, but more frequently it is multifid 

 at the apex ; sometimes it is deeply lobed along the margin, with the 

 lobes deeply crenate or incised ; sometimes it is extremely short and 

 almost reniform ; sometimes there are a number of short reniform 

 divisions ; sometimes the sori are abbreviated near the margins ; 

 sometimes they are quite marginal, or even appear on the upper 

 surface. Many of these monstrous forms can be reproduced from 

 spores, and sometimes it is said that when part of the frond is normal 

 and part abnormal, the spores on the normal part produce normal 

 plants and vice versa. 



Hart' s-tongue Fern. 



Tribe Y.— BLECHNE^]. 



Oaudex not growing in advance of the fronds, the stipes of which 

 is not articulated to the caudex and does not separate from it. Sori 

 medial, oblong or linear, straight or flexuous, continuous or more 

 rarely separate, attached to the side of a vein which is parallel to the 

 midrib and margin of the frond or segment, which is flat, or with its 

 margins reflexed over the sori. Indusium attached longitudinally to 

 the veins, or absent. 



