How to Know the Ferns

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.

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.

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.

CHAPTER VII
THE LADY FERN AND THE SPLEENWORTS

The sub-family Asplenieæ has a large number of representatives in the United Kingdom. There is much division of opinion as to the real place of the Lady Fern. Many botanists consider that the species is a true Asplenium. Others regard it as the solitary British representative of the genus Athyrium. All Fern growers support the latter view. Some of the small Spleenworts are quite common.

Athyrium or Asplenium Filix-fæmina. The generic name of the Spleenworts is derived from the Greek word splene, “the spleen,” this having reference to the fact that in the old days a medicine derived from the leaves was held to be a remedy for diseases of the spleen. The specific name is simply a combination of two Latin words—Filix, “a fern,” and fæmina, “a woman,”—that is, “Lady Fern,” a name no doubt given on account of the elegant appearance of this species, particularly when it is compared with the Male Fern (N. Filix-mas). The Lady Fern.

Although it is altogether more fragile in appearance, the growth of the Lady Fern bears a resemblance to that of the Male Fern. We notice the same tall fronds rising from a stout root-stock covered with brown scales. In a favourable situation, such as a damp hedge, these fronds may grow to the length of four feet, or even more. They are of a beautiful pale green colour, and being of a thin texture soon disappear at the approach of winter. The stipes is usually about one-third of the whole leaf, and is sometimes of a brownish colour. The stalk is remarkable for its brittle nature. The outline of the fronds is lanceolate, and they taper very decidedly towards the base as well as at the tip. The leaves of the Lady Fern are bi-pinnate. The pinnæ are placed either in pairs, or alternately, on opposite sides of the rachis, and these in turn are divided into toothed pinnules. In the case of both the pinnæ and the pinnules the distinctiveness is lost towards the upper portion.

The sori are very abundant, but as these are small they should be carefully examined. They occur about midway between the central vein of the pinnule and the margin of the leaf. The indusium is not clearly linear, being more in the shape of a horseshoe, but this character can only be recognized before the delicate covering has started to shrivel. There are a huge number of variations of the Lady Fern, but many bear a more or less striking resemblance to the type.

Happily the Lady Fern is common in many parts of the United Kingdom. Often it is to be found growing surprisingly near to towns, though its pretty green foliage makes a strong appeal to the eye of those vandals who go about uprooting every fern which they see. It is of easy culture in the garden. The fronds of the Lady Fern develop in the spring of the year.

Asplenium septentrionale. The specific name means “northern,” and this has reference to the fact that the species is more abundant in the north than in the south. The Forked Spleenwort.

The fronds of this Fern are of a thick leathery nature, but they are rarely more than about two inches in length. As they are produced in thick tufts, the individual plants will often cover a good deal of space, considering the diminutive nature of the plant as a whole. The stipes is considerably longer than the leafy portion of the frond; this latter is of a very simple nature, being composed of two or three blades which fork out something on the lines of a stag’s horn. The plant is quite unlike any other British Fern, although its foliage bears a singular resemblance to that of the Buck’s Horn Plantain (Plantago coronopus), a common enough weed, especially on waste patches near to the sea.

On the underside of the narrow blades are produced the sori; these are present in the form of lines on either side of the mid-veins. At first they are covered with scale-like indusia, but as the sporangia ripen the protecting shield is thrown aside. Finally, the capsules spread out so as to cover almost the whole of the underside of the blade.

The Forked Spleenwort finds its home in the fissures of rocks and in the crevices of old walls. It is, however, a rarity, less uncommon in the North than in the South of England. Now and again it has been recorded in great abundance in a particular spot, and it is difficult to understand why the species is not more wide-spread in its distribution. The Forked Spleenwort can be grown in gardens if suitable rock crevices are provided. The plant is an evergreen species.

Asplenium germanicum. It is uncertain what is the derivation of the specific name germanicum; in some quarters it has been said that the name was given owing to the fact that the Fern is a very popular one in Germany, though whether this is a true explanation cannot be stated with certainty. The Alternate-leaved Spleenwort.

This species is somewhat larger than the last-named, though it is hardly so striking in appearance, owing to the comparatively small number of fronds which are produced. These will, as a rule, be about four or five inches in height, and they arise from a tufted root-stock. The stipes is about the same length as the leafy portion of the frond. The rachis bears alternately curious wedge-shaped pinnæ. At the broad end these pinnæ are toothed, and these segments are more pronounced on the lower than on the upper pinnæ. The fronds are of a fairly tough texture.

On the backs of the pinnæ we shall find the sori, two or three lines of the collections of sporangia being present on each division of the frond. At first these are covered with an indusium, but as the capsules ripen this is thrown away and the clusters join together in one mass.

The Alternate-leaved Spleenwort is very rare. It is, however, known to occur in a few rocky localities in England and Scotland. Probably it is often overlooked by the few people who visit the more inaccessible parts. It has proved to be rather a difficult subject to grow, and it has a most annoying habit of dying off suddenly, even when given a great amount of care. Probably the real trouble is that it is given too much water; good drainage would go a long way to meet the difficulty. The fronds of the Alternate-leaved Spleenwort sometimes survive the winter.

Asplenium ruta-muraria. In this case the specific name simply means “wall rue,” and refers to the resemblance which the Fern bears to the Common Rue (Ruta graveolens). The Wall Rue.

A very charming little species, with which most people who take the least interest in Ferns are probably familiar. In reality this plant is a rock Fern, but it often finds a congenial home on old walls. The Wall Rue has a tufted root-stock which is furnished with a quantity of fibrous roots; these often force their way for a considerable distance into the crevices. From the root-stock arise a number of little fronds; where the situation is dry, and the battle for existence is a hard one, these may not be more than a couple of inches in length. In damp situations the fronds might measure three times as much. Where the examples are dwarfed the stipes will be about the same length as the leafy portion, but in a well-developed instance it will be much longer. The colour of the fronds is of a dark green colour, and these are of a somewhat leathery nature. In a fair-sized example the frond is twice pinnate, the pinnæ are definitely stalked, and the pinnules are roughly wedge-shaped, being somewhat toothed at the lip. The Wall Rue is excessively variable, and in exposed places it is possible to find plants bearing fronds which are only divided once, the pinnæ being segmented.

The sori are in the form of lines which branch out from the lower part of the pinnule in a fan-shaped manner. The indusium disappears as soon as the sporangia become mature, and eventually the sori may spread over the whole of the back of the pinna or pinnule.

The Wall Rue is really a very common Fern, but it is often overlooked when hiding in the dark crevice of some old wall. The plant has a wonderful habit of adapting itself to dry conditions. It is of easy cultivation if it can be given an open and well-drained situation. The Wall Rue is an evergreen plant.

Asplenium adiantum-nigrum. In this case the specific name is formed of two words, the first of which belongs to the true Maidenhair Fern. As has already been explained, it comes from a Greek word which means “unwetted,” a reference to the fact that the fronds do not become damp when it rains. The word nigrum, of course, simply means black, and is obviously an allusion to the colour of the leaf-stalks of this Fern. The Black Maidenhair Spleenwort.

A very pretty Fern, which in some ways is to be regarded as the most attractive of all the Spleenworts. The species varies a good deal according to the situation in which it is growing. Thus in dry hedge-banks it will be a comparatively small Fern, whilst when growing in damper situations—such as by the side of a waterfall—it will be very much larger. The root-stock is thick and is densely covered with scales, and from it arise the leaf-stalks, which are black towards the base. The stipes is usually about the same length as the leafy portion. In the varying forms the fronds range from about four inches to a foot, or even more, in length. In the smaller examples the fronds are twice pinnate, whilst the larger leaves may be thrice pinnate. The general outline of the frond is triangular, and the pinnæ, which are arranged alternately on either side of the rachis, are somewhat similar in outline. The pinnules are shaped like wedges and have toothed lobes.

If we turn up a frond of the Black Maidenhair Spleenwort we shall discover the sori situated on veins which issue from the mid-veins of the pinnules. In their early days these clusters are distinctly in the form of lines, but after the throwing off of the indusia they rapidly mature and spread to such an extent that the whole of the under-surface of the pinnule is covered. Often an entire frond appears to be completely brown on its underside.

The Black Maidenhair Spleenwort is an exceedingly common Fern. It occurs in almost all parts of the United Kingdom, although, of course, near towns it is usually rooted up. The species is of very simple culture and will be quite happy on an ordinary rockery. The Black Maidenhair Spleenwort retains its fronds throughout the winter.

Asplenium lanceolatum. The specific name has reference to the fact that the outline of the frond is lanceolate. The Lanceolate Spleenwort.

This is a species which in its early days is sometimes confused with the Black Maidenhair Spleenwort. The fronds, which are lanceolate in outline and about four inches to a foot in length, arise from a tufted root-stock; the stipes is usually about a third of the frond. The colour of the stipes, and also part of the rachis, is bright brown, and this contrasts finely with the handsome green of the leafy portion. The actual length of the fronds will vary to a considerable extent, this depending upon the amount of moisture available. The design of the frond, when it is developed, shows by its lanceolate outline a marked feature which distinguishes it from the triangular outline to be seen in the case of the Black Maidenhair Fern. The frond is twice pinnate, and as a rule the pinnæ are opposite; these are roughly egg-shaped in form. The pinnules have serrated margins.

The sori are placed on veins which branch out from the mid-veins of the pinnules. At first the collections of sporangia are long and narrow, and covered with a white indusium. As the capsules mature the sori spread out over the under-surface of the frond.

The Lanceolate Spleenwort is usually met with near to the sea or in mountainous districts. It is rather local, although it sometimes occurs in great plenty on damp rocks. It is said not to occur in Scotland. In a suitable rocky corner there is no reason why the Lanceolate Spleenwort should not be grown in a garden. The situation should be well drained, but a sufficiency of water is needed. The Lanceolate Spleenwort remains green throughout the winter.

Asplenium marinum. The specific name marinum has, of course, reference to the fact that the Fern is to be found near the sea. The Sea Spleenwort.

This is an interesting and a most beautiful species, often growing abundantly from the roof-crevices of caves on the coast. The root-stock of this plant is stout, and from it are produced a large number of fine black roots which penetrate into the rocky fissures. The fronds are, as a rule, four or five inches in length, though in favourable situations they may be very much longer. The stipes is somewhat short, hardly ever more than a third of the length of the frond, and sometimes less than this. In most cases the stipes is of a purple colour, and the leafy portion of the frond is of an exceptionally fine green shade. The leaves are freely produced in tufts and are roughly lanceolate in outline. The fronds of the Sea Spleenwort are only once pinnate, the pinnæ—which are usually about an inch in length—being, as a rule, oblong in outline. They are, however, decidedly variable in form, some being egg-shaped. A curious feature of the pinnæ is that they are unequal in shape at the base, the lower part appearing to have been cut off whilst the upper portion is greatly enlarged. Between the lower pinnæ the rachis is winged, but this feature disappears at the tip of the frond where the pinnæ run together.

The sori are to be found on the underside of the pinnæ, arranged in lines on either side of the mid-veins. During the early days the cluster of sporangia is covered with very distinct indusia, but as the capsules ripen, these disappear.

The Sea Spleenwort is hardly ever found at a great distance from the sea. It is most common on the coast of southern and western England, sometimes appearing in great abundance in rocky caves. The species also occurs in other parts of the United Kingdom where there is a rocky coastline. Happily it often grows in inaccessible places, and even where the plant can be reached with ease it is extremely difficult to tear the root-stock from its crevice. It seems to be almost impossible to grow the Sea Spleenwort in the open garden, although it is readily cultivated under glass. The species is evergreen in habit, though the foliage will not stand frost.

Asplenium ceterach. The specific name is considered to be a corruption of Chetherak, a name given to this Fern by early medical writers. In some books the species is called Ceterach officinarum. The Scaly Spleenwort.

This is the most distinctive of all the Spleenworts. The root-stock of the plant is tufted and scaly, and from this are sent down dense masses of roots which penetrate into the remote recesses of the wall or rock crevice where the Fern has made its home. The fronds vary greatly in length, and in a very exposed situation may not be more than an inch or so; in a sheltered and moist place they will be two or three times this size. The outline of the fronds is lanceolate. Strictly speaking, the fronds of the Scaly Spleenwort are pinnatifid, the leaf being designed with rounded lobes and deeply cut intervals. When held lengthways an idea is obtained of the wonderfully regular manner in which the cutting-out of the lobes has been devised. The segments of the fronds occur alternately on the rachis.

At first glance it is not an easy matter to discover the sori, for the back of the frond of this Fern is completely covered with brown scales; these are, however, white in the early days of the leaf.

By removing the scales it is possible to see the groupings of the sori; these are arranged in the form of rough lines. There is no very clear indication of an indusium, and indeed when one considers the protective scales this hardly seems to be necessary. It is generally considered that the scales on this Fern act in a protective manner during the long spells of dry weather. In such a condition the fronds of the Scaly Spleenwort appear to be trying to roll right up, whilst the lobes close in towards each other. To all appearance the plant is dead. It soon revives, however, after a good shower of rain.

The Scaly Spleenwort is to be looked for in limestone districts, where it occurs on old walls or amongst rocks, often in great abundance. It is said to be less common in Scotland than in other parts of the United Kingdom. Under cultivation the Scaly Spleenwort often comes to grief through excessive moisture; it is most happy in a crevice on a rockery. The Scaly Spleenwort is an evergreen plant.

Asplenium trichomanes. The specific name is probably formed of two Greek words—thrix, “a hair,” and manos, “soft.” This is doubtless a reference to the hair-like nature of the leaf-stalks. The Maidenhair Spleenwort.

This is a very familiar Spleenwort, not infrequently sold as the English Maidenhair. The plant has a stoutish root-stock, from which grow a quantity of fine roots; these often penetrate for a long way into the crevices of the rocks, or between the building materials of an old wall. The length of the fronds varies from a few inches to nearly a foot. The stipes is very short and is extremely brittle. On either side of the rachis, which is of a deep purple colour, the pinnæ are produced. These are borne on a very short stalk and are of an oval shape, being about half an inch in length. The margins of the pinnæ are occasionally slightly toothed. As a rule, the pinnæ are set in opposite pairs on either side of the rachis. A curious feature of the leaf-stalks of the Maidenhair Spleenwort is that they do not decay at once when the pinnæ fall off. Thus it is often possible to find thick bunches of them on the root-stock looking like so much dark hair.

The sori are placed in the form of lines on veins which branch from the mid-vein of the pinnæ. In the early days the clusters of spore capsules are covered with indusia; as the capsules mature these are thrown off, and finally the sori may spread over the back of the pinnæ.

The Maidenhair Spleenwort is an exceedingly common Fern in many parts of the United Kingdom. It is often found on old walls in great abundance. Happily it is not an easy plant to exterminate; for, owing to the long roots already mentioned, it is a difficult matter to dislodge a plant from its crevice. In the garden the Maidenhair Spleenwort is perfectly happy on a rock ledge; it should not be given a large amount of moisture. The Maidenhair Spleenwort is an evergreen species.

Asplenium viride. Here the specific name is formed of the Latin word viride, “green,” obviously a reference to the bright colour of the fronds. The Green Spleenwort.

In some respects this species resembles the Maidenhair Spleenwort, though there are certain important distinctions. In the first place, there is the bright green colour of the whole plant; this is very different from the dull shade of the Maidenhair Spleenwort. The Green Spleenwort also grows in damp situations, and would not be at all happy on the top of a wall. Most distinctive of all, the Green Spleenwort has a bright green rachis to its fronds, although the stipes has a tendency to be purple in colour. In other respects the two plants are very similar. We notice the same narrow frond with the rounded pinnæ set on either side of the rachis, sometimes in pairs and sometimes in alternation. The margins of the pinnæ are inclined to be notched.

The sori are narrow, and when young are covered with an indusium. It is said that even when ripe the sporangia hardly ever spread over the entire surface of the pinnæ, as is to be seen in the case of the Maidenhair Spleenwort.

The Green Spleenwort is a much rarer species than the Maidenhair Spleenwort. It grows in wild and often mountainous situations in various parts of the United Kingdom. As has already been indicated, it likes rather damp situations, and is to be seen at its best in moist places. The Green Spleenwort is rather a difficult plant to grow in the garden, and it is happiest of all in a humid greenhouse—unless, of course, a very favourable situation can be found out of doors. The fronds of the Green Spleenwort generally last through the winter.

Scolopendrium vulgare. In this case the generic name is derived from scolopendra, the Latin name for a “centipede”; this has reference to the supposed resemblance of the lines of spore cases to the legs of a centipede. The specific name is, of course, simply Latin for “common.” The Hartstongue.

This is certainly one of the most familiar of all British ferns. Almost alone amongst the well-known species, the plant has an uncut frond. The leaves rise from a tufted root-stock which generally stands well above the level of the ground. The length of the fronds varies considerably, and in a mature plant which has found a damp corner these are sometimes two or three feet in measurement. Where the plant has found a home on a dry wall, however, it may be a very diminutive affair. As a rule, the stipes will be about one-third of the whole frond, the leafy portion being long and tongue-shaped. At the tip the frond ends in a point, whilst towards the middle the leaf swells out again, narrowing once more towards the base and finally expanding again into a couple of ear-shaped projections. The rachis of the Hartstongue Fern is a very prominent feature, and at the back of the leaf appears in the form of a ridge.

From the rachis arise veins which run out to the borders of the frond, and parallel to these are the linear sori. Although at first sight this is not very apparent, the brown lines are composed of two sori which practically join together. The pairs of sori are covered with pairs of indusia which, on the maturity of the sporangia, open out opposite to each other. As a rule the sori are most plentiful on the upper portion of the frond of the Hartstongue. There are an immense number of varieties of the Hartstongue, some of which are familiar garden subjects. In a wild state it is not an uncommon thing to find fronds which are abnormal, and some of these show a greater or less tendency to develop fronds which are branched.

The Hartstongue is an excessively common Fern, often occurring in the greatest abundance. It is said to be less frequent in Scotland than in other parts of the United Kingdom. Naturally it is of the simplest culture in the garden.

There is much division of opinion as to the position of the Fern, which we must now consider. In some quarters it has been given a place among the Spleenworts, but many authorities consider that the Hard Fern is the solitary British representative of its class.

Blechnum spicant. In this case the generic name is derived from a Greek word blechnon, a name for a Fern. The specific name, spicant, is from the Latin spica, “a point.” The application of the name is realized when the sharply-pointed pinnæ are examined. The species is in some books called Lomaria spicant and Blechnum boreale. The Hard Fern.

This species has a rather thin root-stock, from which arise large quantities of wiry roots. From the crown the two kinds of fronds are sent up. We may first consider the barren fronds: these vary according to the conditions under which the plant is growing, and range from a few inches up to one or two feet in height. The stipes is very short and it is of a brownish colour, with a few scales. The leafy part of the frond is narrowly lanceolate, tapering slightly at the point but more decidedly at the base. On either side of the rachis, which is green, are arranged the pinnæ; these are not opposite, but are in alternation. The pinnæ are narrow and oblong, and at the tip the frond tends to become pinnatifid, whilst at the base the pinnæ are little more than rounded lobes. The frond has been not inaptly likened to a double comb. The fertile frond has much the same outline as the barren one; it is, however, easily distinguished by its greater length and the extremely narrow pinnæ. These fertile fronds arise from the centre of the clump and are at their best about the month of June. They are very erect in their growth. The sporangia are borne along the margins of the pinnæ of the fertile fronds. The borders of the pinnæ seem to curl over and protect the sporangia; by a close examination it is easy to discover the independent indusia. When the spore capsules ripen they spread so that the whole of the underside of the pinnæ is covered. The texture of both the barren and the fertile fronds of the Hard Fern is very leathery.

The Hard Fern is, of course, a very common species, to be found all over the United Kingdom. The plant is of a simple culture and is evergreen in habit.

CHAPTER VIII
THE POLYPODIES

There must be very few people, indeed, who are not familiar with the leading British representatives of the sub-family Polypodieæ. It is difficult, indeed, to make a journey in any part of the country without sooner or later coming across some plants of the Common Polypody. Some other species of the genus Polypodium are not uncommon in certain parts of the country.

Polypodium vulgare. Here the generic name is derived from two Greek words—polys, “many,” and pous, “a foot.” This has been given to the plant on account of the fact that the creeping and branching rhizomes from which the fronds arise are in some way suggestive of feet. The specific name, of course, means “common.” The Common Polypody.

This species has a creeping root-stock which in its young days is covered with brown scales. From the underside there grow masses of fibrous roots, which often spread for a considerable distance. The rhizome may be very much branched, and from it alternately on either side arise the fronds. These may be quite short—about five or six inches—or, on the other hand, they may be as much as one or two feet in length. The stipes is usually about the same length as the leafy portion of the frond and is of a plain green colour. The general outline of the leafy part of the frond is lanceolate, tapering to a point, broad in the centre and narrowing slightly at the base. The frond of the Common Polypody is cut in a pinnatifid manner. The lobes, which are more or less rounded at the tip, are separated by openings in which the leafy portion is cut almost down to the rachis. Now and again the margin of the lobes is somewhat toothed.

On the back of the frond are to be found the sori. These are disposed on both sides of the mid-ribs of the lobes; they are circular in shape and have no indusia or covering of any kind. When the sporangia are young the sori are of a very pale yellow colour; this changes to a rich golden-brown as the capsules mature. The sori are mostly confined to the upper portion of the frond, and on account of their bright colouring add very much to the appearance of the leaf. There are a large number of varieties of the Common Polypody.

The Common Polypody will, of course, grow in almost any position. It often finds a home amongst the branches of old oak trees, whilst it seems to be equally happy on the wall or the hedge-bank. It is of fairly easy culture in the garden, though the plant likes a well-drained situation. The Common Polypody is an evergreen species.

Polypodium phegopteris. Here the specific name is formed of two Greek words—phegos, “a beech,” and pteris, “a fern.” This is, of course, a rendering of the popular name, though why the species has been called the Beech Fern nobody seems to know. Certainly the species is not like a Beech, neither can it be said to grow in association with this tree. The Beech Fern or Mountain Polypody.

This species has a slender creeping rhizome from which arise the dainty light green fronds. The fronds vary from about six inches to a foot in length; the stipes is longer than the leafy portion, and is of a light green colour. The outline of the leafy part is triangular in form, and on either side of the rachis are the tapering pinnæ. At the top the frond is pinnatifid, whilst the lower pinnæ are deeply cut. A very distinctive feature of the Beech Fern is the way in which the lower pair of pinnæ point downwards away from the tip of the frond.

Nearly the whole of the underside of the frond bears the sori. These are placed quite near to the margins of the lobes of the pinnæ. Like all the Polypodies the clusters of sporangia have no indusia.

The Beech Fern cannot be called a common species, though it is often abundant in certain localities. It is much more frequent in Scotland than elsewhere, and may be looked for hopefully in almost any moist wood. It also occurs abundantly in some parts of the North of England. Unless the Beech Fern can be given a moist position it is not an easy plant to grow in the open garden. It is, however, successfully cultivated in the greenhouse. The plant dies down in the winter, and the new fronds do not appear until somewhat late in the spring.

Polypodium dryopteris. Here the specific name is derived from two Greek words—drus, “an oak,” and pteris, “a fern.” Here again it is not easy to see a resemblance between this fern and an oak, unless it be that the newly-developing fronds are in colour something like the delicate green of the tree when it is decked in its new foliage. The Oak Fern or Three-branched Polypody.

This plant has a thin creeping rhizome from which the fronds arise. The stipes is of a pale green colour, and it is usually longer than the leafy portion. Actually the frond is divided into three branches, each of which is triangular in shape and pinnate towards the base, becoming pinnatifid at the tip. The pinnæ are deeply segmented. The unrolling of the frond is a very novel feature of this Fern, each branch at this time appearing to be like a small coil of wire. In its early days the golden green colour of the frond is very much pronounced, but as the leaf ages a deeper tone is assumed.

The sori are disposed near to the margins of the lobes of the leaves, and these are circular and without indusia. The lower pinnæ of the Oak Fern do not point downwards, as is seen in the case of the Beech Fern.

The Oak Fern is common in many parts of Scotland, and is to be seen carpeting the ground of many a moist wood. It also occurs in England chiefly in the northern counties. In some parts of Wales it is to be found in plenty, but the species is said to be rare in Ireland. The Oak Fern grows in a damp and shady spot in the garden, though it is often more happy in a pot. The fronds of the plant die down in winter, and the fresh ones do not start until late in the spring.

In some books a species called Polypodium calcareum (The Limestone Polypody) is described. In some quarters this plant is regarded as a variety of P. dryopteris, as it is similar in some respects. Mr. C. T. Druery considers it to be a distinct species. The chief points of difference are said to be the following. The whole plant is larger in growth, whilst the green of the fronds is not such a golden colour, even in the early days. Also the pinnæ are not arranged so definitely in the form of three branches, as is to be observed in the case of the Oak Fern. Finally, the unrolling of the frond does not present the appearance of three little balls, seeing that each pinnæ unfolds separately. The Limestone Polypody occurs chiefly in the North of England.

Polypodium alpestre. The Alpine Polypody. This is a most remarkable species, in that it bears a singular resemblance to the Lady Fern. By some authorities it is positively regarded as a Mountain form of the Lady Fern. The reason for linking the species with the Polypodies is found in the rounded sori, which have no indusia. The Alpine Polypody has a short tufted root-stock, and from this arise the fronds, which may be a foot or even more in height. The stipes is very short when compared with the leafy portion, and it is covered with brown scales. The general outline of the fronds is broadly lanceolate, and they are twice divided. The pinnæ are arranged in alternation on either side of the rachis, and these are divided into pinnules with blunt points. The pinnules have toothed edges. The sori are chiefly situated near to the inside border of the pinnules. Those who consider that the Alpine Polypody is a form of the Lady Fern call the species Pseudathyrium alpestre.

The Alpine Polypody seems to be exclusively confined, as far as the United Kingdom is concerned, to the highlands of Scotland. It is sometimes to be found at an altitude of four thousand feet above sea-level. In spite of its restricted locality the Alpine Polypody is an easy subject for the garden, if it can be provided with a well-drained situation.