INTRODUCTION. 
11 
DISTRIBUTION. — “ Here the distribution of an order is that of a single 
species only, the Osmunda regalis, which prevails chiefly in the south-west of 
England, and perhaps the south-west of the Highland tract ; being very frequent 
on the coasts of Cornwall, and occurring in plenty about some of the lochs of 
Argyleshire, and on adjacent islands. The range of the Osmunda extends the 
whole length and breadth of Britain ; but whether it be found on the islets north 
of Sutherland, or west of Islay, is yet unknown. Still, there are considerable 
tracts along the eastern side of England and Scotland, where it is either extremely 
scarce or wholly wanting. The Osmunda differs from most of the dorsiferous 
Ferns in being adapted to thrive in marshy places, and to flourish on the sea 
shores, sometimes only just above high water line. Notwithstanding that it 
endures the boreal climate of Sutherland, (a county in which the specimens are 
said to be small,) the Osmunda is perhaps never seen much above the sea level in 
England, although the general vegetation of the coast in Sutherland approximates 
closely to what is observed at 1000 or 1200 feet of elevation in England. In 
respect to frequency of occurrence, the Osmunda may rank nearly on the level of 
its allies, the Botrychium and Ophioglossum, though rather less frequent than 
either of these.’’ — Mr. Watson’s MS. 
OPHIOGLOSSACE7E. 
( Contains Botrychium and Ophioglossum.) 
Ophioglossace.*, Br., Lind., 8{c .; — Ophioglosse.e, Spreng .; — Filices, 
Linn., Smith, Hook., 8fc . ; — Staciiiopterides, Willd . ; — Bivalva, Hoffm.; 
Valvat.e, Web., Mohr . ; — Agyr.at.-e, Swz. 
STRUCTURE. — The plants contained in this order are very near in general 
structure to that of the last, yet in some important particulars they differ very 
materially. Their root is smooth, fibrous and yellow, not creeping nor hairy : 
and gives rise to one or at most two fronds only, which issue from the ground 
with a straight and not circinate vernation. The frond half way up divides into a 
leafy expansion. The thecae are sessile, opaque, ringless, smooth, collected into 
a simple or compound spike, and are supposed to arise, as in the last- described 
order, from the leaf itself. The thecae open by a regular transverse fissure, emitting 
smooth, yellow, very minute seeds ; those of Botrychium in twos or threes. The 
roots of both genera are perennial, the stems herbaceous and hollow. The stem of 
Botrychium containing its ducts in two bundles near the centre ; that of Ophio- 
glossum in from five to seven bundles, seated between two cylindrical cuticles, and 
by their pressure forcing the inner one into a tortuous form. 
DISTRIBUTION. — “ The two plants comprehended in this small order differ 
from most of the Polypodiaceae, by growing chiefly in more open situations ; 
their upright habit perhaps rendering them less adapted to banks and rocks. 
