European Ferns. 
in nature and construction it is precisely like the large stems of the tree-ferns of tropical and 
sub-tropical countries. From beneath the surface of the ground the caudex gives off stolons, 
which run for seven or eight feet, and propagate the plant. 
The fronds are of two kinds — barren and fertile, the latter bearing the sori. The 
barren fronds are very numerous, and form a magnificent vase-shaped crown of foliage of 
very regular arrangement. They are of large size, sometimes attaining a length of as much 
as five feet, though usually about three feet, and are elegantly curved outwards. The petiole 
is short, and is dilated at the base, where it joins the stem, and there covered with nearly 
black scales, which are not torn or lacerated ; on section, the petiole presents two oblong curved 
vascular bundles. 
The general form of the frond is broadly oblong, gradually diminishing in width at the 
base, and abruptly narrowed at the apex ; it is divided into very numerous pinnae. These are 
all sessile ; the lower ones are small and distant, usually turned downwards, and at the very 
base of the petiole become brown and scale-like ; the main pinnae are four or five inches long, 
narrow, slightly curved towards the apex of the frond, and tapering to the point ; they are very 
numerous, and vary considerably in proximity to one another, being usually just in contact 
but not unfrequently so closely placed that they overlap. Each pinna is simply cut into 
numerous, simple, oblong, blunt segments, which are not again divided or toothed. The general 
appearance of the whole frond is not unlike that of the common Male Fern, but it is a paler 
and brighter green. The venation of the segments of the pinna is remarkable in being quite 
simple, not forked or reticulated. 
The fertile or sporiferous fronds are few in number, usually from three to six; they 
appear in the centre of the tuft in the autumn, and are not mature till September and 
October. Their height is not more than eighteen inches or two feet, and they are erect and 
straight, with a stout, stiff rachis, broader and flatter than in the barren fronds, deeply 
channelled in the lower portion. The pinnae are very numerous, and crowded closely together; 
in fact, the whole frond is a much contracted form of the barren ones. The large pinnae are 
about one-and-a-half to two inches long, but the upper and lower ones much shorter ; all 
are sessile and directed upwards, and are dark brown in colour. In outline they are narrow 
linear, obtuse at the apex, and with a rather knotted appearance, each knot corresponding with 
a segment ; in substance they are nearly cylindrical, the margin being rolled in underneath and 
covering over the sori. The venation is simple, the central vein of each segment giving off 
several undivided veinlets on each side, and upon the middle of every one of these is borne 
a sorus. The sori are round and confluent into a mass, the receptacles very thick and cylin- 
drical. It was long considered that no indusium was present ; but this integument is now 
known to occur as an exceedingly delicate membrane over each sorus, separating it from its 
neighbour. The spores are oval and yellow. Occasionally fronds are met with intermediate 
between the barren and fertile condition, bearing a few sori as contracted though still herbaceous 
pinnae. 
There is little variation in this fine fern, and no forms are sufficiently distinct to have 
received separate names. The plant itself has, however, been very unfortunate in this respect. 
It is the Osmunda Struthiopteris of Linnaeus, who thus placed it in a genus where it is 
impossible to retain it. The German botanist, Hoffmann, transferred it to the genus Onoclca 
as O. Struthiopteris ; in cultivation it is generally known by Wildenow’s name for it, Struthiopteris 
qennanica. The separate genus Struthiopteris is distinguished from Onoclca by the simple 
venation of the barren fronds. The plant has several more names. 
