CURIOUS FACTS IN VEGETATION
(From Part xiv. of Knowledge for the People, or the Plain Why and Because.)
Why is it improper to consider the turnip a real bulb?
Because it is an intermediate stem which swells into a bulbous form. Turnips have not been cultivated in England, in fields, more than a century; but this agricultural practice now yields an annual return which probably exceeds the interest of our national debt.—Sir Walter Scott.
Why is the Cauliflower so named?
Because of its origin from caulis, the stalk of a herb. Colewort is of a similar origin.
Why are the stems of the Cabbage tribe considered wholesome food?
Because their acrid flavour is dipersed among an abundance of mucilage. Cabbages were commonly used among the ancients, and Cato wrote volumes on their nature. The Indians had so much veneration for them, that they swore by cabbages, and were therein as superstitious as the Egyptians, who gave divine honours to leeks and onions, for the great benefits which they said they received from them.—Lemery on Food.
Why do Cabbages emit a strong animal odour?
Because they contain a great quantity of azote or nitrogen, one of the ultimate elements of animal matter, and strongly characterized in the destructive distillation of horn, hoofs, or bones.
Why do not the leaves of the Cabbage remain wet, after being immersed in water, and again taken out of it?
Because they are powdered with a slight layer of resinous matter, similar to that which covers certain fruits, and, in particular, plums and grapes. Their sea-green colour is also attributed to this resinous layer.
Why is Quassia so called? Because it was named in honour of a negro, Quassia, a drunken doctor, who discovered the virtue of the wood in curing malignant fevers.
Why is the Ice plant so called?
Because its stem is covered with soft tubercles, or excrescences, which have a crystalline appearance.
Why do the leaves of some trees fall very early?
Because they are articulated to the branch; that is, they do not unite with it by the whole of their base, but are simply fixed to it by a kind of contraction or articulation; as in the maple and horse chestnut.
Why do leaves fall at the approach of winter?
Because a separation takes place, either in the foot-stalk, or more usually at its base, and the dying part quits the vigorous one, which is promoted by the weight of the leaf itself, or the action of the gales that blow in autumn on its expanded form. M. Richard explains the cause more philosophically: "Although the fall of the leaves generally takes place at the approach of winter, cold is not to be considered as the principal cause of this phenomenon. It is much more natural to attribute it to the cessation of vegetation, and the want of nourishment which the leaves experience at that season, when the course of the sap is interrupted. The vessels of the leaf contract, dry up, and soon after, that organ is detached from the twig on which it had been developed."
Why do some trees, as the Oak, the Beech, and the Hornbeam, retain their leaves to a late period of autumn?
Because the life of the twigs on which they grow is not sufficiently vigorous to throw them off, after the brown colour indicates that they are dead.
Why have some plants been termed the Poor Man's Weather-glass?
Because they shut up their flowers against the approach of rain. Linnaeus, however, thinks, that flowers lose their fine sensibility, after the anthers have performed their office, or when deprived of them artificially. Sir James Smith also observes, that some species are sometimes exhausted by continued wet; "and it is evident that very sudden thunder showers often take such flowers by surprise, the previous state of the atmosphere not having been such as to give them due warning."
Many flowers have a regular time of opening and shutting. We have already mentioned the Marigold; the goat's-beard is vulgarly called "John go-to-bed at noon," from its closing at mid-day; and at the Cape of Good Hope there is a "four o'clock flower," because it invariably closes at that time. The common daisy is, however, a readier example, its name being a compound of day's and eye—Day's-eye, in which way, indeed, it is written by Ben Johnson. It regularly shuts after sun-set, to expand again with the morning light. Thus,—
The little dazie, that at evening closes.—Spenser.
By a daisy, whose leaves spread,
Shut when Titian goes to bed.—G. Withers.
Leyden sings of moist or rainy weather foretold by daisies. Thus we may examine a whole field, and not find a daisy open, except such as have their flowering nearly over, and have in consequence lost their sensibility.
The daisy is one of the pet flowers of the poets. Chaucer is ecstatic in its praise, and calls it his "owne hartes' rest;" Burns, "Wee, modest, crimson-tipped flower;" and Wordsworth, in beautiful and touching simplicity, has addressed several poems to "the poet's darling."
Appended to Richard's valuable "Elements," is the Horologium Florae, (timepiece of Flora,) or a table of the hours at which certain plants expand and shut, at Upsal, 60 deg. north latitude. The earliest Meadow Salsafy opens from 3 to 4 A.M.; and closes from 9 to 10 A.M. The latest A.M. is the Mesembryanthemum Modiflorum, (used in the manufacture of Maroquin leather,) which opens 10 to 11 A.M., and closes at 12 P.M. The latest opening P.M. is the Cactus Grandiflorus, 9 to 10 P.M., and closing at 12 P.M., thus remaining open only two or three hours. Other flowers, we may add, are so peculiarly delicate, as scarcely to bear the contact of the atmosphere.
Forster, in his "Researches about Atmospheric Phenomena," notices several prognostics of the weather by plants. Thus, Chickweed has been said to be an excellent weather-guide. When the flower expands freely, no rain need be feared for a long time. In showery days the flower appears half concealed, and this state may be regarded as indicative of showery weather; when it is entirely shut, we may expect a rainy day. If the flowers of the Siberian sowthistle remain open all night, we may expect rain next day. Before showers, the trefoil contracts its leaves. Lord Bacon observes, that the trefoil has its stalk more erect against rain. He also mentions a small red flower, growing in stubble-fields, called by the country people wincopipe, which, if it opens in the morning, assures us of a fine day.