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quite as large as the lowest pair, and the size scarcely diminishes
till the fourth or fifth pair is reached. The pinnæ have
evident stalks, commonly two to four lines long : they are usually
exactly opposite, but may sometimes be found separated
as much as half an inch. The secondary pinnæ, pinnules, or
leaflets, are perfectly smooth, and of a rather firm chartaceous
texture : they vary a good deal in shape and in size, and many
supposed species have been founded principally upon differences
of this kind ; but, to any person who will devote a day to gathering
fronds of this fern in the marshes and along the waters
of almost any township in New England, it will appear a useless
and superfluous task to try to distinguish even any well-
marked varieties. The pinnules vary in length from three-quarters
of an inch to two inches and a quarter (in plants of the
United States), and in breadth from three lines to eight, the
shorter ones being not always the narrowest. The commonest
shape is oval-oblong, rounded at the apex, and the base unequal,
being obliquely truncate or broadly rounded on the upper side,
and more or less cordate on the lower. Other fronds, especially
those from Florida and the Carolinas, will have oblong-lanceolate
pinnules, with the apex sub-acute, and the base very unequal.
Sometimes both sides of the base are cordate, and
specimens, with a distinct rounded auricle on the lower side of
the base are by no means lacking. The absence of this auricle
was formerly relied on to distinguish the American O. spectabilis
from the European 0 . regalis ; but, while the auricle is
certainly less common here than in Europe, it may readily be
found in almost any district, and it is certainly impossible by
its aid to separate the plants of the two continents. The
edges of the pinnules are commonly finely crenulate - serrulate ;
but sometimes the serrulations are scarcely perceptible. Besides
the auricle just referred to, the margin of the pinnules
occasionally bears two or three short rounded lobes in its lower
half, just as is often the case in European specimens.
The veins are free, and usually fork once close to the midvein,
and the upper veinlet again before reaching the margin ;
but in broader pinnules the lower veinlet is also forked; and,
if the pinnule be auricled or lobed, the forking will be repeated
a third and even a fourth time. The apices of the veins end
most frequently in the sinuses between the teeth, but sometimes
in the points of the teeth, as in Milde’s European var.
acuminata.
The fertile fronds are of the same height as the others,
and usually have the three or four lower pairs of pinnæ exactly
like those of the sterile fronds ; but the upper part is
transformed into a bipinnate or tripinnate panicled mass of
fructification. In the normal fructiferous panicle the green-
leaf tissue is entirely wanting, the ultimate divisions being all
thread - like, containing no chlorophyll, and entirely covered
with sporangia. But it frequently happens that some of the
pinnæ are but partly contracted,- and produce abundant sporangia
along their margins, while yet presérving a truly foliaceous
character. This may happen either at the base of the panicle,
or in its upper portion : when the latter is the case the upper-
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