HARDY FERNS AND MOSSES. 
316 
but its distinct habit demands it shall not be crowded. Propa- 
gate by spores or division. The second species is the Sensitive 
fern of North America — O. sensibilis. It has obtained its 
common name from the rapidity with which its fronds shrivel 
when cut. These fronds are of two very distinct types. The 
barren, first produced, are broadly triangular in general out- 
line, deeply and irregularly cut into finger-like segments ; the 
texture is thin and papery, and the colour a soft pleasing green. 
Though the roots are hardy the fronds are very sensitive to 
frost, and late spring or early autumn “ snaps ” shrivel them. 
A sheltered position is therefore advisable. The barren fronds 
are sparingly produced, and are reduced to a spike bearing 
what look like so many round balls or buds. These fronds are 
more permanent, and last till the following season. Both are 
produced along a thick creeping rhizome, the division, of which 
forms an easy mode of increase. The fronds average about 
2ft. in height, half of which is stalk. Remarks as to soil and 
moisture above are applicable here. 
Ophioglossum vulgatum (Adder’s Tongue Fern).— 
This is similar to the botrychium, but has a flat, broad green 
leaf and a simple spike. It is a native found in damp meadows. 
The treatment recommended for botrychium is applicable here. 
Osmunda (Royal Fern). — The Osmundas are marsh 
ferns, requiring boggy soil on the margin of a pool or stream, 
though they can be made to flourish without these, providing 
copious supplies of water are given all the year round in dry 
weather. O. regalis, our native kind, grows 3ft. high, with 
broad bi-pinnate fronds, the apices of which are contracted 
into fertile spikes. O. r. cristata is a crested form of dwarfer 
habit. The following are North American species. O. cinna- 
momea, 2^-ft. high ; pinnate barren fronds ; fertile, distinct, 
narrow, slender, upright, and grow in the centre, and being 
taller give a fountain-like appearance. O. Claytoniana, pinnate 
fronds of a lovely green colour, the fertile ones have some 
segments fertile, the others foliated ; 2^ft. high. A handsome 
plant. O. gracilis is a slenderer form of O. regalis ; height, 2ift. 
Propagation is effected by sowing the spores, which are freely 
produced. All those named are deciduous. 
Polypodiurrt (Polypody). — Mostly easily grown ferns, 
and the type — P. vulgare — is easily accommodated, and also 
distinct in appearance. P. alpestre (Mountain Polypody) much 
resembles a small Lady fern in shape and general appearances, 
is deciduous and very hardy. Flexile is a broader, less divided 
and more flaccid variety. P. Dryopteris Oak Fern) is another 
native kind, with triangular, three times cut fronds on long 
wiry stalks, produced from a creeping rhizome. Colour a fresh 
