A Dictionary of Choice Ferns. 
205 
DAVALLIA — continued. 
and slenderer than those of lany other kind, and the pale 
green colour of which forms a striking and most pleasing 
contrast with the red tinge of their slender, round, flexible 
stalks. This variety is a native of the Straits Settlements. Its 
light, drooping habit makes it one of the best of stove 
basket Ferns in cultivation ; its roots are averse to loam, 
and are also very sensitive to the effects of drought. 
D. Tyermanni. 
This very handsome greenhouse species, native of the 
West Coast of Africa, is popularly known as the Bear's- 
foot Fern, on account of the narrow, silvery-white scales 
with which its wide-creeping rhizomes are densely clothed. 
Its fronds, of a bright green colour and somewhat leathery 
texture, are somewhat scantily produced ; they are tri- 
angular in shape, 4in. to 6in. long, four times pinnatifid, 
and borne on naked stalks 2in. to Sin. long and of a 
reddish colour. The sori, disposed at the base of the ulti- 
mate lobes, are covered by hemispherical involucres that 
are free at the sides. 
DENNST^DTIA. See Dicksonia. 
DIACALPE 
This genus is composed of a solitary species. 
Its chief peculiarity is the hard, g-lobose, entirely 
closed covering, which at last bursts open irregularly, 
and is affixed to the sorus by a small point of contact. 
D. aspidioides. 
This stove species is a native of the Malayan Islands, 
Sylhet, Assam, and Ceylon. It is an easily grown plant, 
its requirements being similar to those of the strong- 
growing Aspleniums, and it is very striking on account of 
the rich dark green colour of its massive fronds of a 
graceful habit. These are l^ft. to 2ft. long, including the 
smooth and comparatively slender stalks on which they are 
borne, and about 1ft. broad; they are broadly ovate, and 
of a thin and more or less transparent texture. The 
leaflets, of the same shape as the leafy portion of the frond 
itself, have their leafits of a peculiar oblong-wedge-shape, 
lobed, and as the plant becomes older more or less de- 
current. This handsome Fern is readily propagated by 
its spores, which are abundantly produced and disposed 
one mass to a pinnule, on the midvein of which they are 
attached by a very short stalk. 
