British Perns. 
65 
the terminal pinna? and tip are contracted into mere midribs 
bearing bunches of sori or spore heaps. It is noteworthy that 
tire spores are bright green when ripe, and are shed very early, 
so that when the masses of sori look brown and ripe it is 
usually too late to obtain spores in any number. The Fern 
is, perhaps, our largest, forming, in its favourite habitats, on 
river banks or islands, dense coppice-like groves capable of 
affording cover even to a horseman. In such places it will be 
found that the ground is a dense spongy mass of Moss and 
Fern caudices, the Osmunda forming large rounded masses of 
aerial roots, as well as terrestrial ones. Hence in cultivation 
it must be treated as a bog Fern ; soil mainly peat, and water 
in plenty. It is quite deciduous, the fronds disappearing 
entirely in the winter. It has not been at all prolific in varieties, 
the only really fine one being O. r. cristata (page 64), which 
found its way to a nursery in the winter time in a batch 
of common ones, and thus deprived its finder of the thrill of 
delight its discovery should have afforded, and leaving that 
pleasure to Mr. G. B. Wollaston, who “spotted” it afterwards 
at the nursery for the first time, but failed to become its 
owner, despite a bid of ^25, for those were the happy days 
when British Ferns were appreciated, and the nurseryman 
knew it. Under cultivation it has yielded some sub-varieties, 
one of which bears bulbils, and another has ramose fronds, as 
well as the beautiful crests peculiar to the find. Curiously 
enough the Japanese form of the same species has also yielded 
a pretty but smaller form, O. j. corymbifera, which makes a 
pretty pot plant, but is not so hardy or robust. Spores 
germinate freely and yield abundant plants true to type, but 
they take years to reach a fair size. O. r. undulata, found 
abroad, crispy and pinna? undulate. O. r. rotundata, Ireland, 
Phillips ; pinnules rounded. In addition to the above, a very fine 
form, O. r. decomposita, has been found in Ireland, in 1901, by 
Mr. Cowan. This has the usually smooth-edged pinnules 
deeply crenate at the base of the fronds, and becoming more 
and more divided towards the tip until complete pinnulets are 
formed. The fertile po.tion consists also of detached bead-like, 
instead of slightly crenate, spikelets. 
