THE MALE FERN AND ITS RELATIVES
Apart from the Bracken Fern which, as we have seen, is abundant almost
everywhere, there are few ferns more common than certain of the leading
members of the sub-order Aspidieæ. The British representatives of this
sub-order include the important genus _Nephrodium_, of which the Male
Fern is the leading example. In addition we have the Shield Ferns
(_Aspidium_), and also some interesting species gathered together under
the genera _Woodsia_ and _Cystopteris_.
_Nephrodium Filix-mas._ The generic name is derived from the Greek
_nephros_, “a kidney,” this having reference to the kidney-shaped indusia
which is typical of the genus; _Filix-mas_, of course, is a name formed
of two Latin words, _filix_, “a fern,” and _mas_, “a male.” In some books
the species is called _Lastrea Filix-mas_, and _Aspidium Filix-mas_. The
Male Fern.
[Illustration: Nephrodium filix-mas. The Male Fern.]
One is almost tempted to follow the example of the early writers of
botanical works and to say that the plant is so well known that “it
needeth no description.” However, such a fine Fern, common though it be,
is certainly as worthy of a notice as any species within the covers of
this book. A very characteristic feature of the Male Fern is its stout
and sometimes very upright stem or caudex. In some plants this is at
times so large that it almost resembles a short trunk. It will readily be
seen that the leaves arise from the outside of the crown of the plant,
whilst at the base of the stalks occur the fibrous roots. Within the
circle of the developed leaves we may find the immature fronds; the least
advanced of these may not develop for three years. The crown of the
plant, as well as the stipes and the rachis, are more or less covered
with brown scales. The length of the fronds of the Male Fern vary
enormously. In a favourable situation the leaves may measure as much as
three feet or more, though an average example would be a good deal less
than this. A well-developed plant should show six or more finely
developed fronds arranged cup-fashion round the central stem. The shape
of the leaf of the Male Fern is roughly lanceolate, broadest in the
middle and tapering at each end. The frond is bi-pinnate, and the pinnæ
are long and taper to a fine point. The pinnules are rather blunt, and
frequently show serrated edges. The upper portion of the frond is
pinnatifid, and in many of the higher pinnæ it is only the pinnules
nearest to the rachis that are distinct.
Practically all the fronds are fertile, though the sori occur chiefly on
the upper portions of the leaves. The brown patches are to be found
arranged in a single line on either side of the central vein of the
pinnules. The sorus is circular and is covered with an indusium which is
notched or kidney-shaped. In the early days the indusium is of a lead
colour, but as the sporangia ripen underneath the brown colouring shows
through the thin covering. The foliage of the Male Fern is of a bright
green tint, changing to a duller shade as the leaves become older. Not
uncommonly the fronds last in good condition through a large part of the
winter when the season is mild.
It is now recognized that the Male Fern may be divided into three
sub-species. These are called _N. filix-mas_ (_true_), _N. pseudo-mas_,
and _N. propinqua_. The differences are not very obvious to the beginner,
but it is said that the first named is only partially deciduous—the
fronds lying prostrate during the winter. In the case of _N. pseudo-mas_,
the fronds are of a leathery nature, and the plant is practically
evergreen in sheltered positions. A well-established feature of _N.
propinqua_ is that the foliage completely dies away in the autumn.
The Male Fern is abundant in all parts of the United Kingdom where the
conditions are in any way suitable. Naturally it is of easy culture in
the garden. The new fronds, which are very pretty when they are
uncurling, put in an appearance in the month of April.
_Nephrodium Thelypteris._ The specific name of this plant is a compound
word derived from the Greek, meaning “ladyfern”; the title probably has
reference to the delicate growth of the species. The Fern is also called
_Lastrea Thelypteris_. The Marsh Buckler Fern.
This is a very attractive Fern, and perhaps the only British species
which frequently grows in water. The Marsh Buckler Fern has a creeping
rhizome from which arise the fronds at intervals; these are of two kinds,
barren and fertile. The barren fronds sometimes reach the length of four
feet, the stipes—which is slender and of a pale green colour—being about
equal to the leafy portion. The fertile fronds are usually shorter. In
both cases the outline of the fronds is the same, being lanceolate. In
each case, too, the pinnæ arranged alternately on either side of the
rachis are cut almost to the midrib. In the case of the fertile fronds
the pinnæ are perhaps a little more contracted; also the margins are
inclined to bend over in such a way as to protect the sori. The clusters
of sporangia are almost circular, and these are borne on the margins of
the lobes on the underside of the pinnæ. The clusters of the sporangia
are covered with small indusia which are slightly notched. The indusia
are soon thrown off when the spore cases start to develop.
The Marsh Buckler Fern is not uncommon, and in suitably moist positions
is often very abundant. It is, however, said to be rare in Scotland. The
species will not flourish in a garden unless something in the way of a
bog can be provided. The fronds appear in the spring and are cut down by
the first frost.
_Nephrodium oreopteris._ The specific name is connected with the Greek
word _oros_, “a mountain.” In some books this fern is also called _N.
montana_ and _Lastrea montana_. In certain districts, varieties of the
species are common. The Mountain Buckler Fern.
In certain respects this species bears a resemblance to the Male Fern.
The fronds spring from a tufted root-stock and their outline is
lanceolate; they are from one to four feet in length. The foliage of the
Mountain Buckler Fern is of a pale green colour. A distinctive feature is
the manner in which the frond of this Fern tapers to a point at both
ends; this is even more pronounced at the base than at the apex. In the
Male Fern any tapering at the base is of a very slight description. The
Mountain Buckler Fern is once pinnate, the pinnæ being continued almost
through the entire length of the stalk; this makes the stipes very short.
The pinnæ, which are generally placed opposite to one another, are cut
very deeply.
[Illustration: Nephrodium oreopteris. The Mountain Buckler Fern.]
The sori are much more abundant on the upper portion of the frond; we
shall find them on the back of the leaf along the margins of the lobes.
They are covered by a very slight indusium, which soon falls off. In the
Mountain Buckler Fern there are to be detected a number of tiny glands on
the back of the frond; these are responsible for rather a pleasant odour
when the foliage is passed through the hand.
[Illustration: Back of frond of a typical Nephrodium. Enlarged.]
The Mountain Buckler Fern grows on heaths, and it has been found in
almost all parts of the United Kingdom. In certain parts of Scotland it
is said to clothe the mountain sides with a wonderfully vigorous growth.
It is not, however, as its name seems to imply, strictly a mountain
species; for it often grows in lowland districts. In cultivation, the
species should be given a moist situation. The Mountain Buckler Fern dies
down in the winter and the new fronds appear in the spring.
_Nephrodium cristatum._ The specific name of this Fern simply means
“crested,” and has reference to the fringed border of the frond. It may
be pointed out, however, that there are not a few Ferns on which the name
_cristatum_ could with more reason have been bestowed. This species is
also called _Lastrea cristatum_. There are a number of forms of this
Fern.
This is a very handsome Fern, and it is a pity that it is not more
common. The fronds are somewhat oblong in outline and have a very narrow
appearance. The root-stock has a creeping habit and sends up tufts of
fronds at intervals. These are very erect, and usually measure between
one and three feet. The stipes is shorter than the leafy portion, and it
bears a few brown scales. The pinnæ are arranged alternately on the
rachis and these are not again divided, although they are very deeply
cut. The colour of the fronds is of a bright green.
The sori are borne in lines on either side of the mid-vein of the lobe.
These are covered at first by an indusium which is notched after the
manner of that of the Buckler Ferns.
The Crested Buckler Fern is very rare, though it is found in a few
localities—chiefly in the North of England. As a rule it occurs on boggy
heaths, and if these conditions can be imitated in the garden, the Fern
grows freely. The fronds are soon cut down by the autumn frosts, and the
new growth does not appear until May.
_Nephrodium spinulosum._ The specific name means that the plant has
little spines. This Fern is associated with other forms, and in some
quarters has not been regarded as a definite species at all. Some of the
varieties, or, as some authorities say, actually distinct species, with
which it is associated have been called _N. dilatatum_ and _N.
uliginosa_. It may be mentioned that some botanists consider _N.
dilatatum_ to be the most important of the three forms. The chief points
about _N. dilatatum_ are the very dark green fronds which are extremely
broad at the base; these spring from a massive caudex. The whole plant
has a very robust appearance, and it is exceedingly common. Providing the
situation is shady this Fern is not particular as to its place of growth.
In the same way the preceding species _N. cristatum_ is regarded by some
as a doubtful species. On this account the beginner will find _N.
spinulosum_ rather difficult to identify, and he must be prepared for
departures from the present type which is here described. The Prickly
Buckler Fern.
[Illustration: Nephrodium dilatatum.]
The frond of this species rises from an erect root-stock. The length of
the leaves varies from one to three feet, and the stipes is usually about
a third of this in measurement. The fronds are triangular in outline, and
it is seen that the pinnules nearest to the rachis are considerably
larger than the upper ones. This gives a very tapering appearance to the
pinnæ. The borders of the pinnules are deeply cut, and the lobes are
adorned with tiny points which give a somewhat prickly appearance. The
lobes are most prominent on the lowest pinnules, and are also far more
pronounced on the lowest pinnæ than they are on the upper divisions of
the frond.
The sori are placed on small veins which grow outwards from the midrib of
the pinnule. These are covered with kidney-shaped indusia. As has been
indicated, the Prickly Buckler Fern varies enormously, both in size and
in almost every other particular.
The Prickly Buckler Fern is not uncommon in parts of England, and is to
be found in damp woods, especially by the sides of streams. It seems to
be less abundant in other parts of the kingdom. It is of easy culture in
the garden. The Prickly Buckler Fern retains its fronds through the
winter.
_Nephrodium æmulum._ Here the specific name is taken from a Latin word
meaning “comparable with”; the reference is to the similarity of the
species of _N. spinulosum_. Some botanists have considered that _N.
æmulum_ is merely a variety of _N. spinulosum_, though the species seems
to be quite distinct. The species is also called _Lastrea æmula_; _L.
fœniscii_ and _L. recurva_. The Hay Scented or Triangular Buckler Fern.
A very characteristic feature of this species are the upturned margins of
the fronds. This makes the leaf look as if it was curled, and at the same
time renders the upper surface of the frond concave. The outline of the
fronds is roughly triangular, being widest at the base. The fronds are
about one or two feet in length, and the stipes is about equal to the
leafy portion. The pinnæ are arranged either in pairs or alternately on
either side of the stalk. These are divided into pinnules which, in some
cases, towards their bases are again divided. The fronds are of an
exceptionally bright green colour, and when bruised give out a pleasant
odour not unlike that of new hay. This is due to the secretions of small
glands which are to be found on the undersides of the fronds.
The sori on the backs of the fronds are arranged in lines on either side
of the mid-veins of the lobes. These are covered with kidney-shaped
indusia.
The Hay Scented Buckler Fern cannot be said to be common, although it has
a wide distribution and may turn up in unexpected places. It is more
abundant in the West of England and in Ireland than elsewhere. It only
flourishes in damp places, and this point must be borne in mind when
planting it in the garden. The Hay Scented Buckler Fern is an evergreen
species.
_Nephrodium rigidum._ The specific name—Latin for “stiff”—is evidently
bestowed on the plant on account of its erect habit of growth. The
species is also called _Lastrea rigida_. The Rigid Buckler Fern.
This species is quite the rarest of all the Buckler Ferns. The plant has
a thickish root-stock from which arise the fronds, usually about a foot
in length. The stipes is, as a rule, about half the length of the entire
leaf; the bare portion of the stalk is thickly covered with brown scales.
The outline of the frond is somewhat variable; on occasion, examples may
be found with a lanceolate outline, whilst others may be distinctly
triangular in shape. The frond is bi-pinnate, the pinnate being placed
rather irregularly on either side of the rachis. The pinnules are blunt
and somewhat oblong in shape; they have serrated edges, but do not bear
any spines.
The sori are placed on either side of the vein in the middle of the
pinnules. These are covered in their early stages with kidney-shaped
indusia. Sometimes this frond has a slight fragrance when it is bruised.
The Rigid Buckler Fern is really a mountain species, and generally grows
at an elevation of more than a thousand feet above sea-level. It is
fairly common in parts of Yorkshire and in some of the north-western
counties of England, otherwise it is a real rarity. It is not difficult
to grow in the garden, but as it flourishes best in a limestone soil it
is a good plan to mix bits of this rock up with the soil which is used.
The new fronds appear in May and die down during the winter.
_Polystichum (Aspidium) lonchitis._ Here the generic name is based on two
Greek words, _polys_, “many,” _stichos_, “order”; the specific name is
also derived from another Greek word—_lonche_, “a spear,” this referring
to the narrow spear-like appearance of the fronds. The Holly Fern.
This species, on account of its regular habit of growth and generally
stiff appearance, is an easy one to identify. The fronds arise from a
tufted root-stock, and in average specimens would be about nine inches in
length. This might be greater or less, according to the conditions under
which the particular plant was living. The shape of the fronds is
narrowly lanceolate, and there is a very short stipes which is thickly
covered with scales. The leaves of the Holly Fern are once pinnate, the
pinnæ being ovate and having a curious ear-shaped enlargement at their
bases on the upward side. The edges of the pinnæ are adorned with a
number of sharp teeth, and this gives a singular spiny appearance to the
whole plant. On this account the Fern has probably received its popular
name of Holly Fern. The colour of the foliage is of a very pretty bright
green tint.
[Illustration: Polystichum lonchitis. The Holly Fern.]
The Holly Fern, as indeed are all the species of _Polystichum_, is very
distinct from a _Nephrodium_ in the matter of its indusium. This is quite
circular, and has no notch; moreover, it is attached to the pinnules by a
short stalk in the centre. Thus it is proper to describe the shape of the
indusium as peltate. The sori are chiefly confined to the upper portion
of the back of the frond, and are situated on either side of the midrib
of the pinnæ. After the falling away of the indusia the sori tend to
spread, so that they may finally cover almost the whole of the back of
the fertile pinnæ.
The Holly Fern is essentially a plant of the mountains, and it is often
found growing in the most exposed situations. It is not common in
England, though it has been found in a few localities in the north. The
species has a much wider distribution in Scotland. The Holly Fern is
evergreen in habit, and its stiff fronds seem to be able to withstand the
severest frost. The plant is rather a difficult one to grow, though if it
can be given a rock crevice it will sometimes settle down happily in the
garden. The foliage of the Holly Fern lasts through the year.
_Polystichum (Aspidium) aculeatum._ In this case the specific name is a
Latin term simply meaning “provided with prickles”—an allusion to the
fact that the fronds are adorned with spines. The Hard Prickly Shield
Fern.
This species is very distinct in its general appearance from the Holly
Fern, though it can at once be seen to be a Shield Fern by the unnotched
indusia which cover the sori. The fronds may be as much as two feet in
height, or even a little more, and these rise from a tufted root-stock.
As a rule the stipes is very much shorter than the leafy portion, and
both it and the rachis are thickly covered with scales. The outline of
the frond is lanceolate, and the colour of the foliage is dark green. A
pretty glossy effect is noticeable on the upper surface. The frond of the
Hard Prickly Shield Fern is twice divided, and the pinnæ are arranged
alternately on either side of the rachis. A distinctive point about this
species is that the upper pinnules at the base of each pinna is larger in
all ways than the other pinnules. The pinnules are provided with sharp
teeth, and it should be noted that they have nothing very decided in the
way of stalks. Actually they are what botanists call decurrent—that is,
tending to run together at the base. In some varieties of this species
the tendency is more marked than in others.
The sori are placed on either side of the mid-veins of the pinnules, and
these are usually confined to about half the upper portion of the back of
the frond.
The Hard Prickly Shield Fern is very widely distributed in England, and
it is to be looked for in shady woods. It is an exceedingly easy plant to
grow, and thrives even in town gardens. The plant is evergreen in habit.
_Polystichum (Aspidium) angulare._ It is not regarded by some botanists
as an established species, but is thought to be a variety of _A.
aculeatum_. However, there are certain differences which appear to be
specific. The Soft Prickly Shield Fern.
As in the Hard Prickly Shield Fern, we find a tufted root-stock from
which grow lanceolate fronds. We notice the same short stipes and the
narrow pinnæ on the leafy portion tapering to a point. In this species it
is said that the pinnules at the base are more nearly equal in size than
is the case with _A. aculeatum_. The pinnules are also more definitely
stalked in the former than in the latter. In the case of the Soft Prickly
Shield Fern, it is noticeable that all parts of the stalk of the
frond—both stipes and rachis, and even the rachides—are covered with
brown scales. It is said, too, that the droop of the fronds is more
pronounced in the Soft Prickly Shield Fern than in the Hard Prickly
Shield Fern.
The arrangement of the sori is similar in both species.
The Soft Prickly Shield Fern has been found widely distributed in England
and Ireland, though it is not so common in other parts of the United
Kingdom. It is easily cultivated, and is evergreen in habit.
_Woodsia hyperborea._ The generic name of this species commemorates the
botanist, Mr. Joseph Woods; the specific name is taken from two Greek
words—_hyper_, “beyond,” and _Boreas_, “the north wind,” without doubt a
reference to the fact that the species extends to the Arctic regions. The
plant is also called _Woodsia alpina_. The Alpine Woodsia.
This is a very pretty little Fern. The tiny fronds, which are not more
than two or three inches in length, spring from a tufted root-stock. The
stipes is rather short and bears a few brown scales. The outline of the
frond is oblong, and the leaf tapers slightly towards the base as well as
at the apex. The fronds are once pinnate, and the pinnæ, which are lobed,
are arranged in rather an irregular fashion on either side of the
leaf-stalk. A curious feature of the Alpine Woodsia is that the fronds
are jointed just above their connexion with the root-stock. When the
leaves die the stalks break away at this point and leave the bases
behind.
When the back of the frond is examined it is evident that we have here a
very distinctive feature. The patches of spore cases are covered with a
very thin indusium, and as time goes on this splits into divisions which
resemble a number of hairs. The fronds are of rather a stout texture for
so small a Fern, and in all parts show an inclination to be hairy.
The Alpine Woodsia is a very rare Fern, and there are only a few recorded
localities of it in England and Wales. It makes its home on moist rocks
on the slopes of high mountains. This little Fern is fairly easily
cultivated. The fronds disappear in the winter.
[Illustration: Woodsia ilvensis. The Oblong Woodsia.]
_Woodsia ilvensis._ The specific name refers to the island of Elba
(Ilva), where this plant was first of all discovered. In some quarters
this plant is held to be merely a variety of _W. hyperborea_. The Oblong
Woodsia.
The fronds of this Fern rise from a tufted root-stock. The stipes is
short, but the frond as a whole is larger than that of the Alpine
Woodsia, and may be as much as six inches in length. The outline of the
fronds is oblong, tapering towards the base and at the apex. Over the
whole frond, both on the upper and the lower side, is a covering of fine
hairs. Usually the hairiness of the Oblong Woodsia is very pronounced.
The covering is so thick on the underside that it is rather difficult to
discover the sori. These have the same curious divided indusia to be
observed in the Alpine Woodsia.
The Oblong Woodsia is a very rare Fern, only to be found in mountainous
districts. It has been reported from a few localities in England and also
occurs in Scotland, usually in almost inaccessible places. The fronds die
down in the winter and break away from the stem just at the crown of the
root-stock.
_Cystopteris fragilis._ The generic name of this Fern is formed of the
two Greek words _kystos_, “a bladder,” and _pteris_, “a fern.” The
specific name is, of course, a Latin word which means “easily broken.”
The Brittle Bladder Fern.
This is one of the most beautiful of all our native Ferns. From a tufted
root-stock which is clad with pale brown scales the fronds arise; these
are about six or eight inches in length and are lanceolate in outline.
This Fern has a habit of spreading in such a way, that each plant may
have several of the tufted crowns from each of which arise a cluster of
fronds. These are sometimes once, and on other occasions, twice pinnate.
The pinnæ are about an inch in length, and where there are pinnules these
are toothed.
We shall find the sori on veins which run from the mid-vein of the
pinnules. The spore patches are rounded and are covered with a curious
indusium, with an inflated appearance towards the centre. It is from the
resemblance of this indusium to a bladder that the plant has received its
popular name. With the disappearance of the indusia the sori tend to
spread over the whole surface of the back of the frond. The general
appearance of the Brittle Bladder Fern is of a delicate nature and it has
a very distinctive appearance.
[Illustration: Cystopteris fragilis. The Brittle Bladder Fern.]
Properly speaking, the Brittle Bladder Fern is a mountain species, though
it sometimes occurs on old walls or in rocky clefts which are not very
elevated. The species is widely distributed in all parts of Great
Britain, though in frequented districts it is soon exterminated. The
Brittle Bladder Fern does not seem to grow very well in the open rockery,
though it is fairly easy to cultivate in pots. The fronds die down at the
approach of winter. There are a certain number of varieties.
_Cystopteris montana._ Here the specific name is formed from the Latin
word _mons_, “a mountain.” The Mountain Bladder Fern.
This is the only other recognized species of Bladder Fern to be found in
the United Kingdom. The species has a slender creeping underground stem
from which arise the delicate fronds. These are usually about four to
eight inches in length, and the stipes is considerably longer than the
leafy portion. The design of the frond is rather like that of the
three-branched Polypody, this being due to the fact that the lowest pair
of pinnæ is much larger than any of the others.
The general outline of the fronds is wedge-shaped, and these are very
finely divided. Indeed in a well-developed leaf the fronds may be three
or even four times pinnate. The pinnules themselves are also deeply cut.
It will be noticed that the lower portion of the frond is always more
freely divided than the upper part; a common characteristic in Ferns.
The sori are very freely scattered on the lobes or pinnules at the back
of the frond, and these are covered with the curious hooded indusia which
were noticed in the last species.
The Mountain Bladder Fern is perhaps the rarest of all our native
species. It is at home in mountainous districts, and seems only to have
been noticed in a few localities in Wales and Scotland. Probably it would
be seen more often were it not that it grows in positions which are not
of easy access. It should be given the same treatment in the garden as
that recommended for the Brittle Bladder Fern. The fronds disappear in
the winter.
In some books a species is given, known as _Cystopteris alpina_ or
_regia_. The plant nearly resembles _Cystopteris fragilis_, although it
is somewhat smaller. This is a very doubtful native, as it seems only to
have been recorded in one or two localities where it may have been
naturalized.