teasel


Значение термина teasel в knolik


teasel - Teasel (Dipsacus sylvestris)
teasel - Above the vegetation at the dykeside curious egg-shaped heads were held aloft on tall stalks. Some of the heads were almost round, these were greenest; some, rather more elongated were ringed round the middle with a purple band; others, so elongated as to be almost cone-like, were purple from tip to base. All were a mass of semi-stiff spines longest at the top of the head and each was enclosed, as it were, in a cage by curving, narrow, green bracts set with small prickles, which bracts arose in a ring at the base and, following the line of the head, though a little outside it, curved inwards at the tip. The tall stalks, ridged and furrowed throughout their length, looked in the bright sunlight as though studded with translucent jewels, for over their whole surface colourless, sharp-pointed prickles caught and reflected the sun's rays. For some distance below the heads the stems were bare - but for those multitudinous prickles - so that the egg-shaped heads in their cages stood out in splendid isolation; then small pairs of leaves appeared, joined directly by their bases to the main stalk, and chiefly remarkable for a shining white midrib which, at the back of the leaf, showed as a thick outstanding rib, on which rib the ubiquitous prickles were again in evidence. But in the lower and larger pairs of leaves a new feature came in, for there the bases joined round the stem and formed basins which were partly filled with liquid, and in which were the carcases of many little insects who had unwarily found a watery grave therein.

Thus, then, did the whole plant stand before us in simple dignity, distinguished, nay, unique, in appearance in this country, if we except its pale, insignificant replica, the Small Teasel, the only other species known here. Indeed, beside our three native species of scabious, there are no other members of its family - the Dipsaceæ - indigenous to our country. Now there are many interesting points about a Teasel, and the first is the meaning of those leafy basins which surround the stalks. No doubt they are primarily intended to serve as a protection against large beasties, such as caterpillars and snails, as well as being traps for small creeping insects, and it is often suggested that this liquid, which contains a good deal of animal matter, is a sort of soup that may in some sort nourish the plant. In proof of this, it is urged that the basins are lined by some five thousand glandular hairs, which hairs are supposed to be for the purpose of absorbing this "soup." But a German investigator has recently thrown new light upon this matter. He points out that really the water is quite fresh in the basins, and keeps so, hence there is no nitrogenous food supplied by it to the plant. In fact, he notes that these very glandular hairs actually exude slime which coats the insect carcases and other matter that fall into the water. Another suggestion has probably something in it. It is that since the Teasel is a lover of moisture and prefers the saturated soil of marshy land, these cups of water up the stem tend to keep the plant always moist, and serve as reservoirs against a possible summer drought.

Even if the glandular hairs do not seem actually to absorb it appreciably, it is difficult not to believe that it keeps the tissues moist to some extent. Our forefathers used to collect this liquor and use it as a cosmetic and an eye-salve; they also named the plant "Venus's Bath," "Venus's Cup," and "Our Lady's Basin."

Let us now pass to a closer examination of the flower heads, choosing for inspection one of those ringed with a broad purple band. The first thing to notice is that each head is divided into an infinite number of four-sided tubes - is pigeon-holed, so to speak - which tubes are formed by boat-shaped bracts set closely side by side, the prow of each being produced into a dark-coloured spine. In the Common Teasel this spine is straight, in the variety known as the Fuller's Teasel it is hooked. So regularly are these bracts placed that a double spiral, one in each diagonal, is formed. The continuation of the stalk forms a thick axis to each head. Above and below the purple band each pigeon-hole is filled with a bud, which lies hidden in its recesses, but in the purple band the buds have developed into full-blown flowers whose purple petals project somewhat beyond the green bracts. It is a curious point worth notice that in the Teasel the earliest line of development is a ring about one-third of the way down, and from thence it spreads upwards and downwards simultaneously.

Arguing from, the daisy and similar floral heads, one would have expected it would have begun at the base and worked upwards, but probably that ring of florets develops first which gets the greatest amount of sunshine, and the shape of the head results in the development starting at this point.

If we isolate a boat-shaped bract and the flower it so carefully protects, we find that each floret consists of a long, tubular corolla made up of four petals marked by four lobes at the mouth, the lowest lobe being somewhat the largest. The upper, exposed part of the petals is a pale lilac colour; the lower, more hidden part, is white. Round the base of the corolla is a very small, green, cup-like calyx. On the first day of the flower's life four stamens protrude heads which are set across filaments standing on the corolla. Pollen is being shed from them. The ovary is below the corolla and a short style rises from it. Honey is produced by the upper part of the ovary and is collected in the petal tube. On the second day the stamens wither and the style grows and takes their place in protruding; the stigma has only one of its branches developed, the other is rudimentary, as it would otherwise get into the way of the bees and hover flies that frequent the heads. Insects that visit these flowers cannot walk over them promiscuous^ because of the stiff spines, so they must dive headforemost into the tubes if they would partake of the honey. In their succession of dives to flowers of different ages they carry pollen from the younger to the older, and thus bring about fertilisation.

As the life of each flower ends, the corolla falls out of its niche, carrying the attached stamens with it. Since those that developed earliest naturally fall first, the ring that showed purple first shows green and empty pigeon-holes earliest, and an ever-widening green band follows upon the purple band. A single seed lies hidden in the recesses of these pigeon-holes, and is mature in the late autumn - the flowers themselves did not come until summer was well on. The ripe seeds are either shaken out by gusts of wind, or jerked out when the head springs back after catching on to some four- or two-footed passer-by. As the plant is a biennial, the seeds of this autumn will be the mature flowering plants of the summer after next.

The thick flower-heads of the Teasel are favourite homes of a certain grub, and these little worms were, in olden days, used as a charm against ague, but this hoary fable, vigorous in Queen Elizabeth's day, was scorned by Gerard, "they are nothing else but most vaine and trifling toies, as myself have proved a little before the impression hereof, having a most grievous ague and of long continuance. Notwithstanding Physicke charmes, these worms hanged about my neck, spiders put into a Walnut shell, and divers such foolish toies that I was constrained to take by fantasticke peoples' procurement, notwithstanding, I say, my helpe came from God Himselfe, for these medicines and all other such things did me no good at all."

But one use of the Teasel, dating from long before Gerard's time, still remains unchallenged even in the most scientific and up-to-date manufactories of to-day, and that is for wool "fleecing." A certain cultivated variety, the Fuller's Teasel (Dipsacus fullonum) - Gerard's "tame Teasell" - is used because, as already mentioned, the spines of its flower-heads are hooked and not straight. These heads are fixed on the rim of a wheel, or on a cylinder, which is made to revolve against the surface of the cloth to be "fleeced," thus raising the nap. No machine has yet been invented which can compete with Teasel-bracts in their combined rigidity and elasticity, and this particular Teasel is grown largely in the West of England, and also imported from France, Africa, and America to meet the demands of our manufacturers. One large firm alone will use twenty thousand Teasel-heads in a year. The word "Teasel" itself is from the Anglo-Saxon taesan, meaning "to tease cloth." "Brushes-and-Combs," "Barber's Brush," "Card Teasel," and "Card Thistle" are synonyms for the plant.

Рядом со словом teasel в knolik


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