Although to most people the study of fossil botany may appear to be an uninviting pursuit, there can be no question as to the importance of the science. It is only in this way that we are able to appreciate the changes which have led up to the existing types of plants. Now the question of the past history of the Vascular Cryptogams is of very special interest in more ways than one. It is, of course, most fascinating to be able to discover what kinds of Ferns flourished, for instance, at the period when the coal deposits were being formed. But, even in a cursory description, it will be quite impossible to allow the matter to rest there. The story of the past, in the case of the Vascular Cryptogams, is closely interwoven with some of the most absorbing phases in the evolution of the Flowering Plants which are such a dominant feature on the earth at the present time.
Quite recently we have had to alter our views materially on the matter of the past history of the Ferns. Within the last few years it has been proved that a huge number of the fossil remains, belonging to the Palæozoic formation at any rate, are not Ferns at all. They belonged to a very distinct race of plants altogether, known as Pteridosperms, even though they had a superficial resemblance to Ferns. After a large amount of patient research it has been demonstrated that these plants bore seeds. The method of flowering and seed-production was vastly different from that which is to be observed in the flowering plants of to-day. The male or pollen-bearing organs were produced straight on the foliage in much the same way as the sporangium of a true Fern is developed. In a similar manner the seeds were borne straight on to the leaf. In some general points these plants also bore a strong resemblance to the Ferns, and it was this which misled the early observers. Without a doubt these Pteridosperms were related to the Ferns, and probably at some remote period the two groups had a common ancestry. There is good reason for believing that at the same time these Pteridosperms were flourishing true Ferns were also well represented.
Now the interesting point about these Ferns is that they were not vastly different, in many ways, from the species which exist on the earth at the present time. Of course certain types, of which we have living examples, were more fully represented than is the case nowadays; on the other hand, some of our most widely distributed families seem to have been at rather a low stage in their history. As well, the remains evidence a large number of very simple species, which perhaps give us an idea of what the original Ferns were like. But on the whole there is nothing to show that our living Ferns are any more developed than the highest types which grew in the coal forests. In these far-away times there were Tree Ferns; but so there are, of course, at the present time.
The early botanists who strove to prove that Ferns were, so to speak, the last development before the Flowering Plants were not, perhaps, very far from the truth. It has been seen that during the period when the coal deposits were being formed there flourished side by side races of true Ferns and Fern-like plants which bore seeds—the Pteridosperms. The point has also been suggested that in all probability these two groups of plants had a common origin. With the coming of later times (the Cretaceous and Jurassic periods) there appeared the Bennettiteæ. These remarkable plants seem to have entirely taken the place of the Pteridosperms, and were an enormous advance towards the Flowering Plants of the present day. Only recently have the Bennettiteæ been properly described and their interesting features fully understood. We have a few representatives of this important group in the Cycads, plants bearing a superficial resemblance to Palms, but actually very different in all other ways. By the manner in which the reproductive organs are produced, and the way in which the scheme is carried out, these Bennettiteæ appear to be a half-way house between the cryptogams and the advanced flowering plants. The stamens bearing the pollen are produced on the fronds very much like the sporangia of Ferns. On the other hand, the seed-bearing structures are collected together into a sort of pistil. This was borne at the tip of the branches and ended their growth, just as happens in the case of Flowering Plants. For some reason which we cannot understand these Bennettiteæ seem to have fallen back in the race for supremacy, for the group is but poorly represented in our modern Cycads and a few allied plants. In all the world there are perhaps not more than about a dozen species, the sole survivors of a race which at one time dominated the world. There seems every reason for thinking that the Flowering Plants arose as an offshoot of the Bennettiteæ, and in some way secured an advantage which enabled them to arrive at their present position.
When we come to consider the past history of the Club Mosses the record is of a different nature to that of the Ferns. Nowadays the Club Mosses are not of great importance in the world, even though, as will be shown later, the number of species is considerable. But when we travel back to Palæozoic times, particularly in the coal period, it is evident that these plants were represented by a number of very large and dominant families. Some of these early Club Mosses certainly came very near to rivalling the Flowering Plants. Probably the tendency of the world to become drier has had something to do with the decline, seeing that in all cases the fertilization is carried out under water. We may gather some idea of the importance of the Club Mosses in Palæozoic times from the fact that in every part of the world where coal deposits have been examined great numbers of the fossil remains of these plants are always discovered. Many of these grew into large trees which were a hundred or more feet in height, sending out great branching shoots above and an enormous root system below.
From a botanical point of view there is no doubt that some of the Club Mosses, particularly those belonging to the family Selaginellaceæ, have approached very nearly to the Flowering Plants. At the present time the existing species, the Selaginellas, bring us up to the very threshold of the dominant group. The lowest division of the Flowering Plants is the Gymnospermæ (which includes the Conifers), and it is interesting to note the points of similarity between a typical Gymnosperm and a Selaginella. To start away with, the Selaginella bears two kinds of spores, each of which in its development has a definite sex character. The smaller ones (microspores) are in their manner of production analogous to the pollen-grains of the Flowering Plant. The prothallus and the male organ (antheridium) are comparable to the special cell-group in the pollen-grain, whilst the spermatozoids approximate to the generative cells. In the larger spores (megaspores) these represent the embryo sac, and the sporangium in which they are produced closely approximates to the part containing the embryo sac in the Flowering Plant. The prothallus which arises from the megaspore in the Selaginella closely resembles the endosperm—a special tissue formed to feed the embryo in the case of flowering plants. The female organ (archegonium) and the cell which it produces are practically identical in both cases. Fossil remains have shown that some of the plants like Selaginella which flourished in Palæozoic times seemed to have come very near to the production of seed. Thus one species which has been described shows a megaspore which was permanently within the sporangium, and which in its general development greatly resembled a fruit. It is, of course, impossible to give more than a very brief outline of some of the chief points in this highly important comparison between the Gymnosperm and the Selaginella. The author trusts that those of his readers who are interested will pursue the study in the admirable textbooks which are now available.
The Horsetails, like the Club Mosses, have had a very important past. Although they are few in number, as far as the species are concerned, they still retain many striking characteristics. Without a doubt the Palæozoic Horsetails grew into giant plants, sending out branches and developing trunks which in some ways are comparable to those possessed by our trees at the present time. These great stems seem to have arisen from rhizomes which travelled about in the mud of the coal jungles. It is usual to refer to these Palæozoic Horsetails as Calamites, owing to the fact that they were originally supposed to bear a resemblance to a reed (Calamus). In the later rocks, such as those which belong to the Jurassic and Triassic periods, occur the Equisetites, plants which were still of great size, but already in some respects showing signs of that decline which has culminated at the present day in the little group of plants which, were it not for a certain robustness of growth, would find it hard to maintain their position at all.
To complete our brief survey of the Vascular Cryptogams it is now necessary that we should review the position of these plants at the present time. Of course in number the Ferns are enormously in advance of all the other plants put together. In the whole world, there are not far short of seventy distinct genera, which include anything between three and four thousand species. The Ferns of the United Kingdom number not far short of fifty, and there are certain variations from the type which some folk are tempted to include as species. For some reasons which we cannot well understand, the Ferns alone amongst the Vascular Cryptogams have been able to hold their own in the world. It is probable that there are quite as many species, and that these are as varied, to-day as has ever been the case. The size of Ferns, as we have already seen, varies enormously. In the tropics and in Australasia there are Tree Ferns eighty feet in height, whilst with many of the Filmy Ferns the size is scarcely larger than that of Mosses. Owing to the fact that it is so necessary in the scheme of reproduction, the majority of Ferns are lovers of moisture. None the less, a few specimens have adapted themselves marvellously to drier conditions. Thus the Bracken will grow on the exposed hillside or cliff-top even where its rhizomes cannot carry the roots to a great amount of moisture. Some of the most interesting species of Ferns are those which grow on walls and rocks, where there is little dampness, during the summer at any rate. Many of these have adopted special devices to cope with drought, such as are to be seen in the Scaly Spleenwort. Here the underside of the frond is covered with hairy scales, and in dry weather the leaves roll up so that the well-protected underside is alone exposed to the sun. After all, however, Ferns are most at home where there is a comparatively deep shade with abundance of moisture. Many species which will grow in somewhat dry situations attain a much finer development under happier conditions.
Luckily many kinds of Ferns are still very common in the United Kingdom. Of course, in much-visited localities the ravages of the trippers have practically exterminated some interesting species in these particular districts. Naturally, one hardly expects to find the Royal Fern flourishing to any extent in the popular holiday haunts—none the less, there are still any number of places where this noble plant “grows like a weed.” The wise man does not talk about such things to his friends. Many of our most beautiful Ferns are saved even in much-frequented places on account of the fact that they grow out of reach. No doubt the graceful Trichomanes of South Ireland would long ago have been stamped out in the Killarney district, were it not for the fact that it often grows in situations which it is almost impossible for anyone to reach.
As far as number is concerned, the living Club Mosses represent a comparatively insignificant group when compared with the Ferns. In all the world there are probably not more than five or six hundred species. These are very widely distributed, and there is hardly any part which cannot offer at least a few species. We have five species of Lycopodium in the United Kingdom. All are rather local, though often enough they occur in great abundance in special localities. Only one (Lycopodium inundatum) ever occurs in lowland districts; all the rest must be looked for on highland moors. A few exotic Lycopodiums grow to a fair size, though this is largely due to the fact that their creeping stems straggle along the ground for a considerable distance. The Selaginellas are a much more important group as far as the world generally is concerned. There are certainly as many as four or five hundred species, and some of these assume almost a shrubby habit. A species from Borneo (S. grandis) is said to attain the height of two feet. In the United Kingdom we have but a single species of Selaginella—S. spinosa, an insignificant little plant. Many exotic kinds are frequently grown in greenhouses, so that a variety of species is within the reach of everybody.
Authorities vary as to the exact number of species which belong to the only genus of the Horsetail—Equisetum; the estimate is never higher than forty. Nearly all these plants are striking in appearance, and some are quite large. A tropical American species is said to attain the height of thirty feet, though this is not so remarkable when one considers that the plant has a climbing habit. In the United Kingdom we have at least eight distinct species. Some of these are exceedingly common, and owing to their vigorous growth will often hold their own against all comers. Indeed, the existing Horsetails are, to use a common expression, “putting up such a good fight” that it is certain they will continue to hold their own for many a long day. Unlike the Club Mosses, the Horsetails seem to be quite happy in the vicinity of towns, and are often seen at their best on railway embankments and in similar situations.
Although the Vascular Cryptogams played an important part in helping to build up our vast stores of coal, it is astonishing to note of what little direct economic value they are to mankind at the present time. In a few parts of the world, where the native races make little or no attempt at agriculture, the root-stocks of Ferns—often rich in starch—are eaten. Thus the Maoris of New Zealand and some of the South Sea Islanders secure a poor kind of sago from some of the Tree Ferns which grow in their districts. The Japanese use the growing tips of the Bracken as food. Years ago, Ferns used to be burnt for potash in this country, and their astringent properties naturally attracted the old-world pharmacist. They are practically useless as fodder on account of their bitter taste, and no animal—except, perhaps, the goat—would think of eating Ferns. In many cases, however, Bracken is used regularly as a bedding-down material for cattle.
Coming to the Club Mosses, it is even more difficult to find that they are of any direct benefit. Some kinds in South America are said to yield a blue dye. Our Common Club Moss is in its huge quantity of spores responsible for the “Lycopodium Powder” which at one time was employed in the making of fireworks. The powder is said to be highly inflammable, but when shaken straight out of the cones it does not always ignite very readily. One of the Horsetails, the Dutch Rush (Equisetum hyemale), was—and perhaps is still—used in polishing, owing to the large amount of silica which is present in its stems. In addition, those who are interested in coast erosion say that the stronger-growing species of Equisetum should be planted to keep clay cliffs from falling. From an ornamental point of view the Ferns and some of the Club Mosses are, of course, of great value. They are widely cultivated in garden and greenhouse, and we may say that these plants make up in æsthetic value what they lack from an economic point of view.
Although the members of the family Hymenophyllaceæ are largely tropical, we are fortunate in having three representatives in the United Kingdom. Two of these, both Filmy Ferns, are not so familiar to people as they might be, if folk were only a little more observant; whilst the Bristle Fern is only to be found in the South of Ireland. All the species require an abundance of moisture, and they attain their greatest perfection on rocks which are dripping with water.
Trichomanes radicans. The generic name is said to be derived from two Greek words—thrix, “a hair,” and manos, “soft”; the specific name is obviously connected with the Latin radix, “a root,” and has reference to the creeping rhizome. The Bristle Fern.
Trichomanes radicans. The Bristle Fern.
This species is quite one of the most beautiful of our native species. Its fronds are very graceful in form, and are of such a delicate texture as to be almost transparent. The general outline of the fronds is triangular in shape. The leaves, varying in length from three inches to a foot, rise from a black, creeping rhizome, which will often cover a large area on a moist rock with a perfect network. The stipes or bare portion of the frond is, as a rule, about the same length as the leafy portion. A singular feature is a wing-like margin which is present on the upper part of the leaf-stalk. The frond of the Bristle Fern is divided three or four times, the first of the pinnæ being placed alternately on either side of the rachis. The pinnules are deeply cut. The veins of the frond are very strongly marked. All the divisions of the leaf are more or less curled, so that the frond as a whole presents a curled appearance.
The sporangia of the Bristle Fern are borne of the veins in the lobes of the fronds. These are produced in curious cup-shaped processes which are really formed by the margin of the leaf. The veins pass right through these receptacles and project beyond the outer edges, thus giving a curious bristly appearance to the frond as a whole.
The Bristle Fern, as has been indicated, chiefly occurs in the South of Ireland. It has been discovered in several counties, though it seems to be best established in the Killarney district. Any attempt to cultivate this Fern will prove a failure, unless the plants are kept continuously under a close glass cover where the atmosphere is saturated with moisture. The Bristle Fern is evergreen.
Hymenophyllum tunbridgense. The generic name is derived from two Greek words—hymen, “a membrane,” and phyllon, “a leaf”; tunbridgense has reference to the fact that the species was first of all noticed at Tunbridge Wells. The Tunbridge Filmy Fern.
The fronds, rarely more than two or three inches long, are of a very dark green colour, and rise from a slender, creeping rhizome which produces immense quantities of fine roots. The texture of the fronds is of a delicate nature, and the veins are strongly marked; in colour the leaves are dark green. The outline of the fronds is roughly ovate; that is, it tends to be broadest towards the centre. The pinnæ branch alternately from either side of the rachis, and these are usually very distinctly lobed. If examined with a magnifying glass it will be seen that the edges of the pinnules are bordered with bristling points.
In the case of the Tunbridge Filmy Fern, the sporangia are gathered in a little cup formed by the margin of the leaf; these are present at the end of the veins which branch out from the mid-veins of the pinnæ.
Hymenophyllum tunbridgense. The Tunbridge Filmy Fern.
The Tunbridge Filmy Fern has a very wide distribution in this country. As a rule the plant grows intermingled with moss, and on this account it is often passed by without recognition. Almost everywhere where there are wet and especially water-splashed rocks one may expect to find this species. The Tunbridge Fern can only be cultivated in the same manner as that indicated in the case of Trichomanes. The plant is evergreen.
Hymenophyllum unilaterale. The specific name is, of course, a Latin word meaning “one-sided”; the application of the term is explained in the following description. (In some books this species has been called H. Wilsoni, out of compliment to a Mr. Wilson, who is said to have noticed the species first of all.) The One-Sided Filmy Fern.
Some botanists have considered that the One-Sided Filmy Fern is merely a variety of the former species, though it is generally considered to be a distinct type. The two plants often grow mixed up together and superficially look very much alike; it is only after a close examination that the differences become apparent. In a general way it will be found that in the case of the One-Sided Filmy Fern the fronds are somewhat more narrow than those of the Tunbridge Filmy Fern. The chief point of distinction is indicated in the popular name:—if the pinnæ are closely examined it will be seen that the upper portion is much more divided than the lower side. Another distinctive point to which attention should be drawn is that in this species the pinnæ show a marked tendency to curve backwards.
A study of the fertile leaf of the One-Sided Filmy Fern will also give us an additional point in the identification. With a magnifying glass it is plainly seen that the margin of the cup-shaped receptacle into which the sporangia are gathered has not the toothed border to be found in the case of the Tunbridge Filmy Fern.
As has been indicated, we may look for the One-Sided Filmy Fern in exactly similar situations to those which suit the Tunbridge Filmy Fern. The former species is said to be more common in Scotland and Ireland than the latter. The One-Sided Filmy Fern is, of course, an evergreen.
Many members of the Fern tribe are of a retiring disposition, and to find them we must search in out-of-the-way corners. This cannot be said, however, of the leading subject under discussion in this chapter, for of all native ferns there is certainly none with a wider distribution than the Bracken. As one of the few ferns not needing a moist situation, the Bracken is able to make itself at home almost anywhere, save perhaps in the vicinity of large manufacturing towns. The sub-family Pterideæ to which the Bracken belongs has not a large number of representatives in the United Kingdom. In the Ribbon Ferns and the Maidenhairs of our greenhouses we have evidence that, as far as the world at large is concerned, the Pterideæ are very numerous.
Pteris aquilina. The generic name is derived from the Greek word pteron, “a wing,” and the specific name comes from the Latin aquila, “an eagle.” The Bracken Fern.
Pteris aquilina. The Bracken Fern.
The height and general outline of the Bracken Fern varies enormously. On exposed hillsides the plant may be barely a foot in height, with leaves correspondingly small. In the sheltered wood it is not an uncommon thing to discover specimens which may be taller than a man. In such cases the fronds may measure as much as four feet at their widest parts. The fronds of the Bracken start to develop—in the South of England at any rate—about April and are fully expanded by Midsummer. During September they turn a beautiful golden brown and finally die altogether, although the leaves do not decay quickly. The Bracken is, of course, a very strong-growing perennial, and the plant has a wonderful system of underground rhizomes. In a strong-growing specimen these rhizomes may be as thick as a finger and are very succulent. They are of a jet-black colour, and at the base of each frond there are sent out a quantity of fibrous roots. The fronds arise from either side of the rhizome, and often not more than one or two are developed in a single season. By examining the rhizome it is possible to discover the buds containing the new fronds for two years ahead.
The fronds of the Bracken Fern are roughly triangular in outline. That portion of the stipes which is under ground is of a dark brown colour, but the portion above the surface is of a bright green tint. The rachis, or foliage-bearing portion of the stalk, represents about half of the whole. On either side of the rachis the pinnæ are arranged in pairs, which are placed nearly but not quite opposite to one another. These pinnæ are divided again, and in very large examples there may be a further subdivision. In all the parts of the frond of the Bracken there is a tendency for less division at the apices of the different portions. It should be noted that the lowest pairs of pinnules, those next to the rachis, are often much modified; they are always small, and in some cases the upper pinnules are missing.
It is along the margins of the lobes of the leaf that the sporangia are produced. There is no proper indusium, the spore cases being protected by the rolling back of the margin of the leaf. When the sporangia are mature the back of the Bracken frond, with its outline of bright brown, is very pretty. The number of spores produced is prodigious, and it is a common experience to find one’s boots covered with the brown dust after walking through the fronds. It is believed that the Bracken is rarely propagated in a natural state by the agency of its spores. The strong-growing rhizomes provide a very effective method of increase, and as has been stated, the Bracken Fern is very quick to claim any land which has been allowed to go out of cultivation.
The Bracken Fern grows almost everywhere in the United Kingdom. It is, however, not able to hold its own on mountains of greater elevation than two thousand feet. There seems to be a popular impression that the Bracken is a difficult plant to grow in the garden. This is not really the case, the trouble, as a rule, arising from the careless manner in which the rhizomes are torn up when the plant is removed. The Bracken is, of course, a useful subject for placing in shrubberies and under trees, but seeing that the travelling rhizomes take up a great deal of room, it should be kept out of the ordinary borders.
Adiantum capillus-veneris. The generic name is connected with a Greek word adiantos, which means “dry or unmoistened,” this having reference to the fact that water rolls off the frond of this Fern. Capillus-veneris simply means “the hair of Venus,” and this doubtless refers to the shining black leaf-stalk and its delicate branches. The True Maidenhair.
Adiantum capillus-veneris. The Maidenhair Fern.
This is one of the most beautiful of our native ferns, and it would probably have been exterminated long ago in this country were it not that it so often grows in inaccessible positions. The True Maidenhair loves a position which is shady and where moisture is abundant. From a slender, creeping rhizome, which is black in colour, the fronds arise. These vary greatly in length, and may measure anything from six inches up to a foot, or even more, according to the conditions in which the plant is living. The stipes, which is usually about the same length as the leafy portion, is jet-black, and like the rachis and all its branchings, is of a very wiry nature. In a moderate-sized specimen the arrangement of the frond would be on the following lines. On either side of the rachis the pinnæ are produced; these usually branch alternately from the central stalk. The pinnæ bear fan-shaped pinnules, which are attached to the stalk of the leaf-division by very fine stalks. The margin of the pinnules is much notched and veined. Where the frond is of a very large size they may be divided three times.
Adiantum capillus-veneris. Enlarged view of back of frond.
In the case of a fertile frond the edges of the pinnules are turned back in a very striking way. If we turn up the fold, it is possible to see the sporangia arranged on the underside. Before the fertile leaf has reached maturity the upper part of the fold has a whitish appearance; finally it turns black.
The True Maidenhair Fern is more widely distributed than is generally supposed in the South of England and in Ireland. It is a delicate species, and, generally speaking, is restricted to those parts of the kingdom where the winter is mild. It may be seen growing abundantly on old quarries in Cornwall, as a rule quite out of reach. The Maidenhair Fern is a fairly easy plant to grow in pots, though it likes a moist atmosphere. Curiously enough, it is not so simple a plant to cultivate as some of the exotic species. The True Maidenhair is an evergreen plant.
Cryptogramme crispus. The generic name of this fern is derived from two Greek words, kruptos, “hidden,” and gramme, “a line,” having reference to the fact that when mature the sori are arranged in lines round the margins of the fronds. The specific name, crispus, is an apt one, when the crisped or curled appearance of the barren fronds is considered. In some books this species is called Allosorus crispus. The Parsley Fern.
A very attractive species bearing both barren and fertile fronds. The former in their general appearance certainly bear a resemblance to Parsley. The Parsley Fern has a thick root-stock from which the fronds grow up in tufts. The barren fronds, which will be considered first, grow to the height of about six to nine inches. The stipes is somewhat longer than the rachis, and it is of a whity-green colour. The outline of the barren frond is roughly triangular, the apex of the leaf being rather blunt. The pinnæ are placed alternately on either side of the main stem, and these bear pinnules which have their margins deeply cut. In very large specimens the fronds may be divided three times. The barren fronds grow on the outside of the tuft. The fertile frond is somewhat taller than the barren leaf, to which it bears a resemblance in its general form. The pinnæ, of course, are very much restricted. At first the sori are rounded, but as they mature they spread so as to form almost unbroken lines round the margins of the pinnules. The sori have indusia, but this is hidden by the margin of the pinnules, which are recurved.
There are few more local species than the Parsley Fern. The plant loves to grow amongst rocks which are often scattered about on the slopes of mountains. Its two chief strongholds seem to be the Snowdon district in Wales and the mountainous parts of Cumberland. In some localities of these districts the plant grows in the greatest abundance, happily often out of the reach of the tourist. The Parsley Fern has also been recorded in the West of England, and it occurs in Scotland. It is easily cultivated, if the fact is borne in mind that it is a rock species needing good drainage. It loses its bright, pretty colouring in a sunny position. The Parsley Fern sends up its green fronds in the month of May, and the fertile leaves follow soon after. The foliage disappears in the winter.
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.
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.
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.
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.
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.