THE ROYAL FERN. 
Genus XVII: OSMUNDA, Linneus. 
Gen. Cuar.—Fructifications paniculate, terminal or lateral on 
contracted rachiform portions of the fronds, or occupying distinct 
contracted fronds. Spore-cases crowded on the margins or over 
the surface of the segments, obovate-globose, pedicellate or sessile, 
having near the apex an incomplete or rudimentary gibbous ring, 
(represented by a few parallel stris), at length bursting vertically 
in two equal hemispherieal valves. Veins forked, from a central 
costa; venules free. 
Fronds coriaceous or herbaceous, pinnate or bipinnate, the pinne 
or segments often articulated; the fertile parts contracted, usually 
rachiform, simple or compound, terminal medial or basal on the 
fronds, or sometimes occupying distinct contracted fronds. 
Rhizome caudiciform or tufted. 
The structure of the fructification in this genus, is quite dissimilar 
to that of all those which have preceded it. The spore-cases instead 
of being completely girt by a jointed ring, which is vertical in one 
group and oblique in another, have only some rudimentary indications 
of the ring on their upper part, these consisting of a few longish 
cells placed side by side. The spore-cases, moreover, burst vertically 
and separate into regular valves. When to this is added, that in 
the British species, the fructification is collected into a kind of 
inflorescence at the upper end of the frond, there can be no difficulty 
in recognising the plant when it comes under examination. 
The genus, however, which is dispersed over the temperate 
regions of both hemispheres, and is not very prolific of species, 
presents some differences of character which serve for sectional dis- 
tinctions. The groups,we have adopted, are :—§ Huosmunda, typical 
of the genus, having the panicles terminal, the upper pinne being 
transformed and sporangiferous, represented by the native O. 
regalis; $ Plenasium, having the lateral pinne transformed and 

