When we come to look at Flowers, with all their special shapes and brightly coloured parts, we are really looking at modified leaves. But they are so very much modified that we have come to consider flowers as things by themselves, and so we will study them later on.
Some plants which do not have true flowers, yet have leaves of two kinds. For example, the “flowering fern” has the usual green leaves and others which form rather brownish golden spikes, and which are covered with spore[6] cases. Then again, some leaves are very specially modified and are changed from the usual structure in order to act as traps for insects (see Chap. XXI.).
Other leaves, instead of being very much developed, or specially developed along some line, are simply reduced, that is, are very little developed indeed. For example, as you saw in the under-ground part of the potato and many rhizomes growing horizontally, the leaves never become large and green, but remain as simple brown scales. Some scale leaves have quite a special work to do in the way of protecting the very young green leaves while they are in the buds, and we will look at these carefully in the next chapter.
We have now seen that leaves, like all the other parts of the plant, can modify themselves in a very great number of ways, and may do many extra pieces of work above and beyond their chief work of food manufacture.
CHAPTER XIV.
BUDS
The proper time to study buds in nature is the spring, but then you will have to wait long to see all the different stages of their slow unfolding. But they can be made to open artificially, and it is really wise to study buds in winter, when there are not so many other things to do. You can arrange this very well if in the late autumn you cut off fairly big branches with buds on them (horse chestnut is particularly good for this) and keep them in a warm room. You must, of course, keep the cut ends of their stalks in water, which you should change every three or four days, sometimes cutting off a piece from the ends of the branches so that they have a fresh surface exposed to the water. In this way they should live for months, and may just begin to unfold and show fresh young green leaves about Christmas time, when the buds on the trees out in the cold are still tightly packed up.
Fig. 62. Buds of the Horse Chestnut beginning to unfold.