Part 12

The Cross-leaved Heath (_E. tetralix_), with downy stems and leaves; the leaves in whorls of four, and fringed with hairs, margins rolled under as in _cinerea_. Flowers pale-rosy, drooping, gathered into a dense head at the summit of the stem. The corollas are pale, almost white, on their under-sides. The anthers like those of _cinerea_, but with two longer processes from the base of each. Bees visit the Heath plants for their plentiful honey, and in pushing their long tongues into the flower in search of it touch their heads against the stigma, which partially blocks the mouth of the corolla. The tongue has to press against one or more of the anther processes, which has the effect of dislocating the series of anther-cells, and allowing the pollen to fall through the opening upon the bee’s head, which is thus ready to fertilize the next flower it visits. This species may be found growing with _E. cinerea_, but usually selects the dampest, boggy spots on the heath. Flowers July to September.

There are two other species, _E. vagans_ and _E. ciliaris_, but they are confined almost entirely to the county of Cornwall; the former distinguished by its _bell-shaped_, not egg-shaped, corolla, and anthers and pistil hanging outside; _ciliaris_ marked by its leaves being fringed with hairs, each hair tipped with a gland.

The name is from _Ereikh_, the ancient Greek name for heath or heather.

=Heather or Ling= (_Calluna vulgaris_).

The Ling is distinguished from the Heaths by the botanist because its bell-shaped corolla is concealed by the longer, equally coloured calyx leaves, and below these are four bracts which resemble a calyx. Its leaves are triangular, very minute and densely packed, overlapping each other. Like the Heaths its flowers are persistent, and are to be found bleached but preserving much of their original form, nine or ten months after they opened. The anthers are short, and contained within the corolla, but the style is long, and protrudes. The tough wiry stems attain considerable size in the highlands of Scotland, where they serve many useful purposes. It flowers from July till September. _C. vulgaris_ is the only species. The genus gets its name from the Greek _Kalluno_, to beautify or adorn, an epithet which all who have visited the moorlands in its flowering season will admit is well-bestowed.

=Mistleto= (_Viscum album_).

Is there a person in these islands above the age of infancy who does not know the Mistleto by sight? Why, then, let it occupy space here? Because it is one of those very well-known things that we only partially know. What percentage of those who took advantage last Yule-tide of the mystic sanctions of the plant, and who consequently think they know it so well, have seen its flowers? or know that it has flowers? True, those of our British Mistleto are not very striking in point of size or showiness; but there are tropical species with flowers both large and brilliant.

In _V. album_ the flowers are of two kinds, male and female, each (with rare exceptions) being borne on separate plants, so that cross-fertilization is imperative. They are both green, and consist of a four-lobed perianth, the male with four anthers attached to the perianth, such anthers opening by a large number of pores. The female flower has the perianth adhering to the ovary, to which the stigma is directly attached, there being no style. The ovary, as all know, develops into the globose white berry, containing the large seed with its viscid coat. These occur usually in twos or threes. The flowers may be found any time between March and May.

This leathery parasite is not very particular as to its host. Quite a large number of trees of different species harbour it, notably the apple; next in favour are poplars, hawthorns, lime, maple, mountain-ash, and very rarely the oak. It has been suggested that the very fact of its extreme rarity upon oak gave oak-grown mistleto its sacred character among the ancient Britons.

=Meadow-Saffron= (_Colchicum autumnale_).

The Meadow-Saffron is more frequently known as the Autumnal Crocus, but we object to the name as conveying a wrong idea of the botanical characters of two distinct genera. Further, there is a true autumnal crocus (_Crocus nudiflorus_), though its claim to be considered British is open to doubt. Like Crocus, Meadow-Saffron has an underground solid stem (_corm_), resembling a bulb, and from this arise the flowers in succession from August to October. These flowers are of a pale purplish colour, and consist of a long slender tubular perianth, enlarging at its upper part into a bell-shape, and this portion is divided into six segments, to each of which a stamen is attached (Crocus has but three). The ovary lies deep within the calyx-tube, and from it arise three long thread-like styles, which are bent over near the tip, the inner side of which is the stigma.

The fruit develops during the winter, and by the spring is ripe. Then when the long, flat leaves make their appearance, the flower-stalk lengthens and brings the ripe capsule above the ground. Sometimes the flowers mistake the seasons and put in an appearance with the leaves in spring, but they are imperfect, and the perianth is greenish-white.

The name is from _Colchis_, where it is said to have grown abundantly.

=Hart’s-tongue Fern= (_Scolopendrium vulgare_).

Hitherto we have dealt only with flowering plants. In these sexual organs are borne in more or less conspicuous blossoms, and, as the result of fertilization of the ovules by the pollen, seeds are produced which give rise to plants exactly like that which bore them. Ferns produce an enormous number of minute bodies, called spores, which are incapable of developing directly into a plant similar to that by which they were produced; but on germination they give rise to a minute green scale, like a liverwort, upon the under surface of which sexual organs appear, and by the mingling of their cell-contents a true bud is formed, from which a true fern-plant is evolved. There are other important points upon which ferns differ from flowering plants, but it is not within the author’s province to deal with them here. Let it suffice to add that as a fruit-bearing organ the leafy portion of a fern differs greatly from the leaves of other plants. To prevent confusion it is termed a _frond_.

The Hart’s-tongue has a frond of very simple character--strap-shaped--consisting of a stout mid-rib (rachis), with a leathery green expansion on either side, the upper end tapering off to a point, the lower divided into two lobes. A large number of thick red-brown parallel ridges on the under surface will attract immediate attention. These are heaps of delicate capsules (_sporangia_), which contain the spores. The Hart’s-tongue is a plant of sandy or rocky hedgerows.

=Maidenhair Spleenwort= (_Asplenium trichomanes_).

A common plant locally on rocks and walls, having a slender dark-brown polished rachis and a large number of roundish-oblong leaflets (_pinnæ_), arranged pinnately on each side. The capsules will be found in short thick lines on the under surface. There is a similar species, the Green Spleenwort (_A. viride_), with a green, softer rachis and the pinnæ distinctly stalked, shorter and paler; growing on wet rocks in mountainous districts.

=Male Fern= (_Nephrodium filix-mas_).

In the Male-fern--so-called by our fathers owing to its robust habit as compared with the tender grace of one they called Lady-fern (_Asplenium filix-fœmina_)--we have an advance in the intricacy of frond-division. Our page is not sufficiently large to represent the whole of the frond, but the portion we give shows that the pinnæ are themselves again divided into _pinnules_. This fern grows to a great size, its rootstock very thick and woody, its fronds erect and three or four feet high. As a rule the rachis and its continuation below the leafy portion (_stipes_) are shaggy with loose golden-brown scales. The spore-capsules are in little round heaps in rows along the pinnæ, and each heap is covered by a thin kidney-shaped involucre. Note in the unrolling of a young frond how beautifully the whole is packed up. The lateral divisions of the pinnæ are rolled each on itself, then the pinnæ are rolled up from their tips toward the rachis, and finally the whole frond is coiled up from the tip downwards. This is the characteristic _vernation_ of ferns, and differs greatly from the packing of undeveloped leaves in the leaf-buds of flowering-plants.

The genus _Nephrodium_ (named from _nephros_, the kidneys, in allusion to the involucre) contains half-a-dozen other British species, of which the most frequent is the Broad Buckler Fern (_N. spinulosum_), with arching fronds, broad at the base, the stipes sparingly clothed with dark-brown scales. Pinnules toothed, the teeth ending in long soft points. Damp woods.

Mountain fern (_N. oreopteris_), with habit of Male fern, but stiffer, and of a yellow-green hue. Spore-heaps near the margins of the pinnæ. High hills and mountain pastures.

=Field Horsetail= (_Equisetum arvense_).

The Horsetails are a small group of flowerless plants, quite distinct from the ferns, though there are certain points in which some resemblance may be traced. We have eight British species out of twenty-five that are known to inhabit the earth. The most widely distributed of these is the Field Horsetail (_E. arvense_), which farmers regard as a pest. In common with the whole tribe it has a creeping underground rootstock, from which more or less erect jointed stems arise. If we break off one of these joints at its natural articulation we shall observe that the ends are solid, and that the upper extremity is crowned by a sheath ending in long pointed teeth, into which the lower end of the next joint fitted. This leaf-sheath, as it is called, is composed of a number of aborted leaves--the only vestiges of leaves the plant possesses. Just below the leaf-sheath a whorl of jointed branches is given off, each constructed in a manner similar to the upright stem. If now we cut our main joint across its middle with a sharp knife we shall find that it is tubular, a central cavity occupying about one-third of its diameter. Between this cavity and the exterior wall is a series of small tubes, somewhat egg-shaped in outline, the smaller end towards the central cavity; alternating with these and nearer the centre are a number of smaller circular tubes. This section should always be made when in doubt as to the species, for the shape and arrangement of these cavities differs in each, as do the external ridges. The accompanying cuts represent half-sections through the stems of the principal British species. In this species there are about a dozen blunt ridges on the stem, extending right to the points of the leaf-sheath. The branches are four-angled, solid, and jointed and sheathed like the main stem. The cells of the cuticle secrete silica in such quantity that the whole of the vegetable matter may be got rid of by maceration, yet the form of the stem will remain in this transparent skeleton of silica. Certain species are used for polishing metal, under the name of Dutch Rushes.

So far we have been describing what is known as the barren stem, because it ends in several unbranched joints, without any fructification. Before these barren stems appeared there arose from the rootstock a stem differing greatly in appearance, usually without branches, and lacking the green colouring matter (_chlorophyll_). It is pale brown in colour, of stouter build, but much shorter, for whereas the barren stem is about two feet in length, the fertile is only a few inches, or at most less than a foot. The leaf-sheath is longer, and the teeth frequently adhere two or three together. The stem terminates in a kind of cone, consisting of many whorls of flat scales, each supported by a central stalk, on the underside of which are arranged from six to nine capsules containing spores. These spores are very curious: they are globular in form, and invested with several coats, the outermost of which splits into four narrow strips, which are highly hygroscopic, and which remain attached to the spore at one point only. These _elaters_, as they are termed, are very sensitive to changes in the humidity of the atmosphere, as may be proved by breathing upon them, however slightly, when they will be seen (through the microscope) to be in active movement. In many ferns the spores require months to elapse before germination takes place; those of Horsetails will germinate in a few hours. Owing to its possession of chlorophyll the spore, if not placed in a situation suitable for germination, perishes in the course of a few days.

The name of the genus is from the Latin, _equus_, a horse, and _seta_, a bristle. The fertile stems appear in March and April, the barren ones at intervals later.

=Lichens= (_Lichenes_). Plate 126.

The rambler will meet with specimens of the Lichen tribes at every turn, when he has got fairly away from the smoke of towns. He will find them on the tree-trunks or rocks and walls, old posts and palings, on thatch and on the ground. Wherever they are found they may be accepted as certificates of the purity of the air. Formerly considered as a distinct type, they are now held by the advanced school of cryptogamic botanists as _commensals_, or partnerships formed between a _fungus_ and an _alga_. They are usually thin crusts, consisting of an upper and a lower epidermis, formed of closely crowded cells, and to the lower layer rootlike filaments are attached. Between these layers are two differing elements; a loose stratum of green cells (_gonidia_), which are said to be _algæ_, and below these a layer of fungoid threads. The contention of the new school is that these _algæ_ have been captured by a fungus and held in bondage, being forced to elaborate starch by means of their chlorophyll from the inorganic material obtained by the rootlike filaments, which starch the fungus is able to feed upon. Some of the green cells are pushed out from time to time invested with a few wisps of fungus-threads, and so reproduce the partnership. It is but right to add that some good authorities on this branch of botany decline to accept these views, and still regard lichens as independent organisms and not partnerships.

The species are very numerous, but their identification is not easy, and requires serious application. The two figured are exceedingly common in some districts. Various species of Cup-moss (_Cladonia_) will be met on heaths, sandy hedge-banks, etc. They have a flat crust-like base, from which arise pale grey tubes or cups, bearing at their tips the bright scarlet, pinky-brown, or even black fruits. A more common form in woods and on banks is _Cladonia pyxidata_, with the tube greatly increasing in width upwards. _Cladonia rangiferina_ is the well-known Reindeer-moss, of inestimable value in extreme Northern latitudes as the food of the useful animal whose name it bears; it may be found in abundance in this country on heaths and hillsides covering the ground beneath the heather.

The other species figured in our plate, the Wall-lichen (_Physcia parietina_), is also very common, forming the familiar orange stains upon walls and maritime rocks. A closely allied species, the grey _Parmelia saxatilis_, is common on tree-trunks: it has been used time out of mind in the production of a brownish-red dye for wools. Several others of the same genus are valuable in a similar direction: our own _Parmelia perlata_, which grows on tree trunks, is largely imported from the Canaries as a dye-weed, and has been sold at as high a rate as £200 per ton.

Lichens are generally of slow growth and long life. Mr. Berkeley kept watch upon a patch of _Lecidia geographica_ for twenty-five years, and found little change in it all that time. The Rev. Hugh Macmillan recounts how he found on the top of Schiehallion a species of lichen encrusting quartz rocks, which exhibited beneath the lichen the marks of glacial action as distinct and unchanged by atmospheric effects as though the glacier had only passed over them yesterday. He suggests that the lichen may reckon its days back very nearly if not quite to the glacial period in Britain!

There are upwards of a thousand British species, and the best list of them will be found in “Crombie’s British Museum Catalogue of Lichens,” of which the first part was published in 1894.

=Mosses= (_Musci_). Plate 127.

Another important tribe of flowerless plants, to which we must be content with merely giving the general characters, for in a volume primarily intended as a guide to wild-_flowers_ we must not occupy too much space with plants that do not produce flowers. At the same time, we believe the non-botanical among our readers will be glad to have a slight introduction, upon the strength of which they may cultivate the closer acquaintance of a most beautiful and interesting group of plants.

A. Three-cornered Hypnum (_Hypnum triquetrum_) is a common species on woodland banks, growing in branching tufts. The stems are well clothed with leaves, which consist of a single layer of cells; there is therefore no necessity for the breathing pores (_stomates_) found on the leaves of flowering plants and giving access to the tissues beneath the cuticle. The leaves of mosses are not provided with stomates; neither are they stalked, but attached directly to the stem by their base. From the sides of the stem at intervals a number of brown, hair-like threads are given off, and each of these ends in a brown, pear-shaped nodding organ, the spore capsule. These capsules are each closed with a lid (_operculum_), beneath which is a double row of teeth, their tips directed towards the centre of the mouth. When the spores are ripe the operculum is cast off, and these teeth erect themselves to allow the minute spores to escape. The teeth (forming the _peristome_) of mosses are always some multiple of four; in Hypnum each row contains sixteen.

B. Beautiful Hair-moss (_Polytrichum formosum_) represents another division of mosses in which the fruits are borne on the termination of the stem or principal branches. In an earlier condition than that figured the capsule is covered with a conical densely-hairy cap (_calyptra_); this is thrown off when the spores are ripe, the operculum follows and the spores are cast.

=Mushrooms and Toadstools= (_Fungi_). Plate 128.

We cannot pretend to do other than call the rambler’s attention to the interesting plants that are variously called mushrooms or toadstools, according to whether they are of the two or three species commonly eaten, or of the multitude concerning which the British public knows nothing, and therefore dismisses them as worthless toadstools.

A. The Fly-Agaric (_Agaricus muscarius_), though in general structure it closely resembles the common mushroom (_Ag. campestris_), is to be avoided as a poisonous species. Its large orange or crimson cap, more or less thickly dotted with whitish flakes, is a very striking feature in woods in late summer and autumn. An examination of the underside of the cap (_pileus_) will reveal a great number of thin yellowish plates set on edge and radiating from the stem to the circumference. Over these plates or _gills_ is stretched a membrane, called the _hymenium_, on which the spores are borne. From this characteristic of the bulk of our mushrooms and toadstools the tribe containing them is dubbed the _Hymenomycetes_.

B. Edible Boletus (_Boletus edulis_). In this group (_Polyporei_) the hymenium, instead of investing gills, lines minute pores or tubes, with which the under surface of the pileus is packed, and in which the spores are produced. Many of the _Boleti_ are edible, but their good qualities are known only to the few in this country. _Edulis_ may be distinguished from other species by a delicate network of raised white lines covering the stem.

C. Jewelled Puff-ball (_Lycoperdon gemmatum_). This species represents a tribe in which the spore-bearing surface is contained within the fungus. In a young state Puff-balls of many kinds are filled with a white creamy substance, and so long as this remains white and does not change colour on being cut the fungus is good to eat, after being cut in slices and fried. When the spores are ripe the Puff-ball splits open at the top, and discloses a hollow filled with brown dust--the spores. Certain species of Lycoperdon attain very large proportions: _L. giganteum_ is abundant in some localities in grassy places, usually measuring nine or ten inches in diameter, but occasionally it exceeds twenty inches, and weighs as many pounds. Slices may be cut from one side of it for several days in succession, but so long as the rooting portion is not interfered with it will continue to grow. _L. gemmatum_ is common on downs or pastures. Readers should be cautioned against eating these small species in a raw state, as such a course has been known to have serious effects.

D. Chanterelle (_Cantharellus cibarius_). This belongs to the same section as the Fly-Agaric, in which the spore-bearing membrane is spread over gills; but in _Cantharellus_ the gills are reduced to thick ribs that run from the edge of the pileus partly down the stem. The whole fungus is coloured with orange-yellow, internally as well as the outside. It is often abundant in woods in summer and early autumn. It is much esteemed for its esculent qualities; but it requires much cooking, and should first be thrown into hot water for a few minutes, then dried on a cloth, and fried or stewed gently.

=Small-leaved Lime= (_Tilia parvifolia_).