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 bracts stands
up straight. These protect the florets. They open and close the flower.
The down pointing bracts protect the flower from ants and crawling
insects.
[Illustration: 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.
[Illustration]
1. Dandelion Flower-head not yet opened.
2. Single Floret of same.
3, 4, 5. Flower-head closed for Seed ripening.
6. Second time of opening.
“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 home, and watch the opening and closing of its
flowers, and the wonderful way in which its travelling seeds are
produced.”
Exercises on Lesson XII.
1. Gather dandelion flowers at different stages of growth. Draw, on a
large scale, a single floret from each,
2. Draw a leaf of the dandelion. Compare it with a primrose leaf. See
if you can make out, from the shape of the leaf, why the plant
is called “dandelion” (_dent de lion_ = “lion’s tooth”).
3. Take in a dandelion plant bearing young flowers. Keep the root in
well-watered soil, or in water only, and watch the growth of
its flowers.
4. Make a list of all the wind-carried seeds you know, and give a
drawing or short description of each.
[Illustration: TROUT]