556 THE FERN FAMILY. [ Botrychium. 
reappearing in south temperate regions. Widely diffused over Britain, but 
not generally common. 7. spring or early summer. 
Ill. OSMUNDA. OSMUND. 
Fronds once or twice pinnate, the leafy part barren; the fructification 
consisting of clustered spore-cases, either in a panicle at the end of the 
frond, or, in exotic species, in some other part of the frond, but always 
distinct from the leaf-like part; each spore-case opening by a vertical 
fissure. 
A genus of few species, natives chiefly of the temperate regions of both 
hemispheres, especially the northern one. : 
1. O. regalis, Linn. (fig. 1275). Royal Osmund, Fern Royal.—The 
perennial stock often forms a trunk rising perceptibly from the ground, 
and sometimes to the height of a foot or more. Fronds growing in tufts, 
erect, from a foot or two in dry poor soils, to 8 or 10 feet when very 
luxuriant, twice pinnate, with lanceolate or oblong segments, 1 to 2 
inches long, rather stiff, prominently veined, either entire or obscurely 
crenate. Fructification forming a more or less compound panicle at the 
top of the frond, usually bipinnate, each spike-like branch representing a 
segment of the frond. 
In moist or boggy places, in western, central, and some parts of southern 
and south-eastern Europe, extending northwards to southern Scandinavia ; 
also in central Asia, North and South America, and southern Africa. In 
Britain, chiefly in the western counties of England and Scotland, in 
Wales, and Ireland, apparently very local in other parts of England, 
and entirely. absent from several counties. 7. end of summer, or 
autumn. 
IV. POLYPODIUM. POLYPODY. 
Fronds (in the British species) either pinnate or ternately divided, with 
the branches pinnate. Spore-cases minute, collected in circular clusters or 
sori on the under side of the segments, without any indusium or involucre ; 
each spore-case (as in all the following genera encircled by an elastic 
jointed ring, and bursting irregularly on one side, having then, under a 
microscope, the appearance of a little helmet. 
A large genus, widely distributed over the globe, only differing from 
Aspidium in the absence of any indusium or membrane covering the sori 
even when young. For the Table of Species, see the Generic Table above, 
p. 554, n. 13. 
1. P. vulgare, Linn. (fig. 1276). Common Polypody.—Rootstock 
thick, woody, and creeping. Fronds about 6 inches to a foot high, of a 
firm consistence, without any scales on their stalk, broadly oblong-lan- 
ceolate or somewhat ovate in their general outline, simply pinnate or deeply — 
pinnatifid; the linear-oblong segments adhering to the main stalk and 
usually connected with each other by their broad bases. Sori rather 
large, of a golden yellow, in two rows along the under side of the upper 
segment. When bearing fruit these segments are usually entire or nearly 
so, and obtuse ; when barren they are often slightly toothed; and mon- 
