FUCUS, in botany, a genus of the order of algae, belonging to the cryptogamia class of plants. The most remarkable species are,
1. The serratus, serrated fucus, or sea-wreck. This is frequent at all seasons of the year upon the rocks at low-water mark, but produces its seeds in July and August. It consists of a flat, radical, and dichotomous leaf, about two feet long; the branches half an inch wide, serrated on the edges with denticles of unequal size, and at unequal distances, having a flat-stalk or rib divided like the leaf, and running in the middle of it through all its various ramifications. A small species of coralline, called by Linnaeus Sertularia pumila, frequently creeps along the leaf. All the species of fucus afford a quantity of impure alkaline salt; but this much less than some others, eight ounces of the ashes yielding only three of fixed salt. The Dutch cover their crabs and lobsters with this fucus to keep them alive and moist; and prefer it to any other, as being destitute of those mucous vesicles with which some of the rest abound, and which would sooner ferment and become putrid.
2. The vesiculosus, bladder fucus, common sea-wreck, or sea-ware. It grows in great abundance on the sea-rocks about low-water mark; producing its fructifications in July and August. It has the same habit, colour, and substance
stance as the foregoing; but differs from it in the following respects: The edges of the leaf have no serratures, but are quite entire. In the disc or surface are immersed hollow, spherical, or oval air-bladders, hairy within, growing generally in pairs, but often single in the angles of the branches, which are most probably air-bladders, destined to buoy up the plant in the water. Lastly, on the summits or extreme segments of the leaves, appear tumid vesicles about three quarters of an inch long, sometimes oval and in pairs, sometimes single and bifid, with a clear viscid mucus interspersed with downy hairs.—This species is an excellent manure for land; for which purpose it is often applied in the maritime parts of Scotland and other countries. In the islands of Jura and Skye it frequently serves as a winter-food for cattle, which regularly come down to the shores at the recess of the tides to seek for it. And sometimes even the flags have been observed, after a storm, to descend from the mountains to the sea-shores to feed upon this plant.
Linnaeus informs us, that the inhabitants of Gothland in Sweden boil this focus in water, and mixing therewith a little coarse meal or flour feed their hogs with it; for which reason they call the plant fwintang. And in Scania, he says, the poor people cover their cottages with it, and sometimes use it for fuel.
In Jura, and some other of the Hebrides, the inhabitants dry their cheeses without salt, by covering them with the ashes of this plant; which abounds with such quantity of salts, that from five ounces of the ashes may be procured two ounces and a half of fixed alkaline salts, that is, half of their whole weight.
But the most beneficial use to which the focus vesiculosus is applied, in the way of economy, is in making pot-ash or kelp, a work much practised in the western isles.
There is great difference in the goodness and price of this commodity, and much care and skill required in properly making it. That is esteemed the best which is hardest, sweet grain'd, and free from sand or earth. The price of kelp in Jura is 3l. 10s. per ton, and about 40 or 50 tons are exported annually from that island. So great a value is set upon this focus by the inhabitants of that place, that they have sometimes thought it worth their while to roll fragments of rocks and huge stones into the sea, in order to invite the growth of it.
Its virtues in the medical way have been much celebrated by Dr. Russell, in his Dissertation concerning the use of Sea-water in the Diseases of the Glands. He found the saponaceous liquor or mucus in the vesicles of this plant to be an excellent resolvent, extremely serviceable in dispersing all scorbutic and serophulous swellings of the glands. He recommends the patient to rub the tumour with these vesicles bruised in his hand, till the mucus has thoroughly penetrated the part, and afterwards to wash with sea-water. Or otherwise, to gather two pounds of the tumid vesicles, in the month of July, when they are full of mucus, and infuse them in a quart of sea-water, in a glass-vessel, for the space of 15 days, when the liquor will have acquired nearly the consistence of honey. Then strain it off through a linen cloth, and rub this liquor with the hand, as before, three or four times a-day upon any hard or serophulous swellings, washing, the
parts afterwards with sea-water, and nothing can be more efficacious to disperse them. Even scirrhoticities, he says, in women's breasts, have been dispelled by this treatment.
The same author, by calcining the plant in the open air, made a very black salt powder, which he called vegetable ethiops; a medicine much in use as a resolvent and deobitruent, and recommended also as an excellent dentifrice, to correct the scorbutic laxity of the gums, and take off the foulness of the teeth.
3. The plicatus, matted, or Indian-grass focus, grows on the sea-shores in many places both of Scotland and England. It is generally about three or four, but sometimes six inches long. Its colour, after being exposed to the sun and air, yellowish, or auburn. Its substance pellucid, tough, and horny, so as to bear a strong resemblance to what the anglers call Indian grass, that is, the tendrils issuing from the ovary of the dog-fish.
4. The palmatus, palmated, or sweet focus, commonly called dusse, or disse. This grows plentifully on the sea-coasts of Scotland, and the adjoining islands. Its substance is membranaceous, thin, and pellucid; the colour red, sometimes green with a little mixture of red; its length generally about five or six inches, but varies from three inches to a foot; its manner of growth fan-shaped, or gradually dilated from the base upwards. Its divisions extremely various. The inhabitants both of Scotland and England take pleasure in eating this plant, without expecting any medical virtues from it. The inhabitants of the Archipelago also are fond of this plant, as we learn from Steller. They sometimes eat it raw, but esteem it most when added to ragouts, oglios, &c. to which it gives a red colour; and, dissolving, renders them thick and gelatinous. In the Isle of Skye it is sometimes used in fevers to promote a sweat, being boiled in water with the addition of a little butter. In this manner it also frequently purges. The dried leaves, infused in water, exhale the scent of violets.
5. The esculentus, eatable focus, or bladder-locks, commonly called tangle in Scotland, is likewise a native of the British shores. It is commonly about four feet long, and seven or eight inches wide, but is sometimes found three yards or more in length, and a foot in width. Small specimens are not above a cubit long, and two inches broad. The substance is thin, membranaceous, and pellucid; the colour green or olive. The root consists of tough, cartilaginous fibres. The stalk is about six inches long, and half an inch wide, nearly square, and pinnated in the middle, between the root and origin of the leaf, with ten or a dozen pair of thick, cartilaginous, oval-obtuse, foliaceous ligaments, each about two inches long, and crowded together. The leaf is of an oval-lanceolate, or long elliptic form, simple and undivided, waved on the edges, and widely ribbed in the middle from bottom to top, the stalk running through its whole length, and standing out on both sides of the leaf. This focus is eaten in the north both by men and cattle. Its proper season is in the month of September, when it is in greatest perfection. The membranous part is rejected, and the stalk only is eaten. It is recommended in the disorder called a pica, to strengthen the stomach and restore the appetite.
6. The saccharinus, sweet fucus, or sea-belt, is very common on the sea-coast. The substance of this is cartilaginous and leathery; and the leaf is quite ribless. By these characters it is distinguished from the preceding, to which it is nearly allied. It consists only of one simple, linear, elliptic leaf, of a tawney green colour, about five feet long, and three inches wide, in its full-grown state; but varies so exceedingly as to be found from a foot to four yards in length. The ordinary length of the stalk is two inches, but it varies even to a foot. The root is composed of branched fibres, which adhere to the stones like claws. This plant is often infested with the fertularia ciliata.
The inhabitants of Iceland make a kind of pottage of this fucus; boiling it in milk, and eating it with a spoon. They also soak it in fresh water, dry it in the sun, and then lay it up in wooden vessels, where in a short time it is covered with a white efflorescence of sea-salt, which has a sweet taste like sugar. This they eat with butter; but if taken in too great a quantity, the salt is apt to irritate the bowels and bring on a purging. Their cattle feed and get fat upon this plant, both in its recent and dry state; but their flesh acquires a bad flavour. It is sometimes eaten by the common people on the coast of England, being boiled as a pot-herb.
6. The ciliatus, ciliated, or ligulated fucus, is found on the shores of Jona and other places, but is not common. The colour of this is red, the substance membranous and pellucid, without rib or nerve; the ordinary height of the whole plant about four or five inches. It is variable in its appearance, according to the different stages of its growth. This fucus is eaten by the Scotch and Irish promiscuously with the fucus palmarum or disse.
7. The proliferus, or proliferous fucus, is found on the shores of the western coast, adhering to shells and stones. The colour is red; the substance membranaceous, but tough, and somewhat cartilaginous, without rib or nerve, though thicker in the middle than at the edges. The whole length of the plant is about four or five inches, the breadth of each leaf about a quarter of an inch. The growth of this fucus, when examined with attention, appears to be extremely singular and wonderful. It takes its origin either from a simple, entire, narrow, elliptic leaf, about an inch and a half long; or from a dilated forked one, of the same length. Near the extremity of the elliptic leaf, or the points of the forked one, (but out of the surface, and not the edge), arises one or more elliptic or forked leaves, which produce other similar ones, in the same manner, near the summits; and so on continually one or more leaves from near the ends of each other, in a proliferous and dichotomous order, to the top of the plant; which in the manner of its growth resembles in a good measure the cactus opuntia, or flat-leaved Indian fig. Sometimes two or three leaves, or more, grow out of the middle of the disc of another leaf; but this is not the common order of their growth. The fructifications are red, spherical, rough warts, less than the smallest pin's head, scattered without order on the surface of the leaves. These warts, when highly magnified, appear to be the curled rudiments of young leaves; which in due time either drop off and form new plants, or continue on and germinate upon
the parent. This plant is very much infested with the flustra pilosa, the madrepora verrucaria, and other corallines, which make it appear as if covered with white scabs.
8. The pinnatifidus, jagged fucus, or pepper-dill, is frequent on sea-rocks which are covered by the tides, both on the eastern and western coasts. It is of a yellow olive-colour, often tinged with red. The substance is cartilaginous, but yet tender and transparent; the height about two or three inches. This fucus has a hot taste in the mouth, and is therefore called pepper-dill by the people in Scotland, who frequently eat it as a salad in the same manner they do the fucus palmarum.
9. The plocamium, or pectinated fucus, is frequent on the sea-rocks, and in basins of water left by the retreats of the tides. Its natural colour is a most beautiful bright red or purple, but is often variegated with white or yellow. Its substance is cartilaginous, but extremely thin, delicate, and transparent. Its height commonly about three or four inches. The stalk is compressed, about half a line in diameter, erect, but waved in its growth, and divided almost from the base into many widely expanded branches. These primary branches are very long, alternate, exactly like the stalk, and subdivided into alternate secondary branches, which are again frequently compounded in like manner, and these divisions decorated with subulated teeth growing in alternate rows, curiously pectinated or finely toothed on the upper side like a comb, the smallest of these teeth scarcely visible to the naked eye. The fructifications are minute spherical capsules, or smooth dark-red globules, scattered without order on the sides of the branches; generally sessile, but some few of them supported on short peduncles. This fucus, on account of its elegant colours and fine divisions, is the species most admired by the ladies who are fond of pictures and mimic landscapes composed of marine vegetables.
10. The filum, thread-fucus, or sea-laces, is found on the sea-rocks, and waving under the water like long strings, frequent on many parts of the coast. The substance of this is opaque and cartilaginous, but not difficult to be broken. The colour, when recent, a dull olive-green; when dry, fuscous, or nearly black; and when exposed for some time on the shores to the sun and air, it becomes yellow, straw-coloured, or white. It consists only of a simple, unbranched, naked, cylindrical stalk, three or four yards long, more or less, from the size of a large fiddle-string to that of a thick whip-cord; smallest at the base and summit; smooth on the outside, full of mucus within; often twisted, and always intercepted by numerous transverse diaphragms, visible when the plant is held between the eye and the light. The fructifications have not yet been discovered; but from the transverse septa in its structure, it is reasonable to suppose this plant to belong rather to the genus of conserua than that of fucus. The stalks, skinned when half dry and twisted, acquire so considerable a degree of strength and toughness, that we were informed the Highlanders sometimes used them for the same intentions as Indian grass.
11. The giganteus, or gigantic fucus, is a native of the Straits Le Maire; and grows on rocky ground, which in those countries is distinguished from sand or
ooze by the enormous length of the sea-weeds that grow upon it. The leaves are four feet long, and some of the stalks, though not thicker than a man's thumb, are 120. Mr Banks and Dr Solander found over some of them which were 84 feet long; and as they made a very acute angle with the bottom, they were thought to be at least one half longer.