656 FLOWERS OF GARDEN AND GREENHOUSE 
MAIDENHAIR FERNS 
Natural Order Finices. Genus Adiantum 
ADIANTUM (the old Greek name, from adiantos, dry, from the fact 
that water rolls off the fronds without wetting them). A genus of about 
eighty species of stove and greenhouse Ferns, with tufted or creeping root- 
stocks, and usually compound fronds, these being twice, thrice, or four times 
pinnate. The rachis and its branchlets are hair-like, whence the popular, 
name of these plants. There is considerable variety in the general form 
of the fronds and of their parts, but as a rule the pinnules are wedge- 
shaped, or rounded or lunate. This gives the plants a character that 
distinguishes them at a glance from other ferns. The sori are marginal, 
as in Pteris, rounded, or oblong. The involucre consists of the turned- 
down margin of the pinnule, to which the sori is attached, so that 
it appears to open inwards. They are found in all Tropical and 
Temperate Regions, but the headquarters may be said to be Tropical 
America. 
The Maidenhair Fern, Adiantum Capillus-Veneris, 
which is widely distributed in the warmer portions of both 
Old and New Worlds, is the only one of the genus that has extended its 
range across the Channel from Europe to the westerly portions of these 
islands. In the humid atmosphere of sea-caves and wet rocks, from 
Dorset to Cornwall, in Glamorgan, in Man and the West of Ireland 
this Fern is occasionally found ; though more rarely every year. This, 
probably, was not a cultivated plant until comparatively recently, for, 
far from the sea, it would not grow out of doors. A. pedatum, 
however, which came from North America prior to 1640, is a more 
hardy subject. It was introduced by the younger Tradescant, and 
was growing in the famous garden at Lambeth two hundred and 
fifty-seven years ago. A. reniforme, from Madeira and Teneriffe, was 
also introduced during the 17th century, for in 1699 Bobart had 
it growing at Oxford. We ceased introducing Maiden-hairs then for 
nearly a hundred years; but the importation of A. villoswm from 
Jamaica, in 1775, seemed to draw attention to the West Indies as a 
source for new species, for in 1793 we brought thence A. macrophyllum, 
A. pulverulentum, A. tenerum, and A. trapeziforme. A. cuneatum, 
which is the one most seprmen: cultivated, came from Brazil in 1820, 
in which year we got A. formosum from Australia; whence also came 
A. hispidulum, in 1822; and A. ethiopicwm, in 1823. Among more 
History. 
