71 



here from warmer lands, being only very locally distributed in 

 situations open to such arrivals from the Atlantic. Cornwall, 

 Devonshire, and Glamorganshire, and the southern and western 

 parts of Ireland, afford its principal British habitats, and it is 

 rarely found very far from the sea ; indeed chiefly in moist mari- 

 time caves and on rocks and cliffs where it is exposed to the 

 spray, and especially where fresh water trickles down their sides. 

 A perpendicular surface seems most favourable to its development, 

 and hence the mouths of old wells and the deserted shafts of 

 mines are occasionally tapestried with its beautiful foliage. Its 

 geographical distribution over the warm and temperate parts of 

 the globe seems, from the testimony of botanists of high repute, 

 to be almost universal. The slender, black, scaly rhizoma creeps 

 and branches slowly in every direction, sending up the light fronds 

 in lax tufts from the extremities, varying in height, according to 

 the situation, from three or four inches to a foot. The hair-like 

 fineness of the rachis and its branches, and their glossy, black, or 

 purplish-black hue, originated both the Latin and English names 

 of the species, but they are not peculiar to it. The pinnules, di- 

 stinct, with capillary stalks, are somewhat flabelliform in general 

 outline, with an unequally wedge-shaped base; they are of a very 

 thin, almost membranaceous texture, and delicate, bright, though 

 rather glaucous green colour, and divided at the top into several 

 unequal segments, which are either serrated or have their extre- 

 mities folded backwards, bearing the sori, which thus appear to 

 form an interrupted marginal line : their true character and posi- 

 tion is given under the generic character, and illustrated by the 

 right-hand enlarged figure on our plate. 



This elegant fern had formerly high medicinal repute, especially 

 as a diuretic and expectorant, but is now only remarkable in an 

 economical point of view as giving name and a slight flavour to 

 the well-known Capillaire, which is prepared by pouring boiling 

 syrup upon the freshly-gathered fronds. It grows abundantly in 

 the South of Europe, where, however, the North American A. pe- 

 datum is often employed as a substitute, being cultivated for the 

 purpose. They are both astringent, and the syrup is esteemed 

 useful in coughs and other pectoral ailments, but a strong de- 

 coction of the latter plant is said to act as an emetic. In the 

 South Isles of Arran, on the coast of Galway, where the Maiden- 

 hair grows profusely in the fissures of the limestone rocks, the 

 people use a decoction of the fronds as a substitute for tea. 



The great beauty of the foliage of the Adiantum would render it 

 a valuable decoration to the ruin, rock, and fountain in ornamental 

 gardening, but, like other maritime self-naturalized species, it is 

 liable to be destroyed by frost, unless planted in warm and shel- 

 tered situations ; indeed, it is scarcely possible to preserve it alive 



