  Uncle George and the boys were having a stroll along a lane where briar and hawthorn and all sorts of wild flowers grew. Although it was an October day the sun was shining brightly, and all along the wayside the golden flowers of the dandelion opened wide to the sunlight. “I thought that the dandelion was an early summer flower,” said Frank. “So it is,” said his uncle; “but this year the autumn has been so warm that our dandelions are flowering a second time. This often happens with many of our wild flowers during an extra mild season. “You ought to dig up one of these dandelion plants, take it home and grow it in a pot. It is a most interesting plant to observe, especially the growth and ripening of its seeds. I see here dandelion flowers in almost every stage of their growth. “If you look you will find among the wide open flower-heads many others which are closed. Let us split a few of these down the centre, and we will find that they are not all alike. “Here is one with a bright yellow tip. This one has not yet opened. If you use your lens you will notice that, like the daisy, this is not a single flower, but is made up of a great many small yellow florets. These florets stand upon a flat round disc, and they are surrounded by two rings of green things called bracts. One set of these Dandelion. “Now, Frank, look at the split flower and tell me what you see with your glass.” “The florets are all of one kind,” said Frank. “They are all strap shaped, and there are a great many of them. The younger florets are in the middle.” “If you were to pull the florets out and count them you would find about three hundred of them in a single flower-head,” said Uncle George.
“Now, take one single floret and examine it, please. It is very like the outer (white) florets of the daisy. But it is more complete. There is a large seed-vessel at the bottom. Just above this there are a great number of long silky hairs. You will see what these are for by and by. The lower part of the floret is tubular, but it opens up into a long yellow strap-shaped petal. There are really five petals all joined together here.” “Oh yes,” said Frank, “at the top of the floret I can see five distinct teeth, and five ridges run down from them. I also see the barrel-shaped ring of stamens.” “Let us gather some more of the closed flowers,” said Uncle George. “Here are two other closed flowers. One of them has a yellow tip, withered and faded almost to brown. The other has a white woolly tip.” “Have these not opened yet?” Tom asked. “Oh yes! they have opened and closed up again. The dandelion opens out to the sun so that flying insects may visit it and carry pollen from flower to flower. When it has received, in this way, enough pollen to enable its seeds to form, it closes up completely and remains closed until its seeds are ripened. During this time the short stalk between the seed-vessel and petal part grows long. If you look again at a single floret you will see that this short stout stack bears the long straight hairs I spoke of. The flower-head closes so tightly that the yellow strap-shaped petal parts of the florets are squeezed together into a bunch. They soon wither. Meantime all the hair-tipped seed-stalks are growing longer and longer. At last they push the bunch of withered petals right out of the flower and it falls off.” Uncle George then gathered a few more closed heads, and, by cutting them open, showed the boys all the stages in the growth of the seeds. “When the dandelion flower-head opens for the last time, instead of a flat golden mass of florets, this is what appears.” As he spoke, Uncle George pointed to a dandelion head which was one huge fluffy ball of stalked seeds. Frank held it up and blew his breath upon it. Immediately all the seeds went sailing through the air. “Why does the flower-head keep closed when the seeds are ripening?” asked Tom. “Because,” answered Uncle George, “not only has the seed to ripen, but a plumed stalk has to be formed by means of which the seed is carried away from the parent plant. These plumes have to be perfectly dry or they would be of no use as sails to the seed. Notice that it is only on dry days that these ‘clocks’ of the dandelion appear.” “But, Uncle George,” said Frank, “are these seeds actually fitted with feathery tops so that they may be carried far away from the parent plant?” “Certainly, my boy. You would not have them all trying to grow in the place where the parent plant grows, would you? There would be no room for three hundred seeds to grow there. Besides that, the parent plant has already exhausted the soil. It is necessary that they should seek pastures new, and therefore the seeds of most plants are furnished with some means of travelling.” “Are all seeds carried by the wind?” Tom asked. “Oh dear no,” Uncle George replied, “plants have many ways of scattering their seeds. Some plants, by suddenly bursting their seed-vessels, shoot their seeds far out; some seeds are furnished with little hooks which grip on to the fur of passing animals; some are carried by birds; but by far the greater number are scattered by the wind. “We shall learn more about these at some future time. Meantime we will grow a dandelion plant at Exercises on Lesson XII.
TROUT |
|
