The Smallest Known Flowering Plant

    While stems, such as the Big Trees or the giant cactus, may be among the largest of nature’s creations they may be also the smallest, as the duckweed that floats on ponds is the tiniest of all flowering plants and its flat expanded surface is wholly stem. Figure 12 on this page better illustrates this strange modification of a stem than words could do.

    From what has been read it will be seen that stems are not “just stems”—they are among nature’s most ingenious devices to secure the survival of the plant. Whether buried in the ground, and producing, almost by stealth, buds that develop into mature plants, or thrusting leaves to the utmost limits of their reach, or climbing by an intricately varied mechanism, or changing their character to suit desert conditions, or floating on the water—it matters not. Each modification of form or use secures to the individual plant its chances to survive; and in most cases its only chance, as anyone may see by the sudden death which follows a series of changes which prevents a stem from performing its proper tasks.

    Once past the entrance it is obvious that we are in one of the strangest of all factories, for none of the rooms are truly square or oblong and their irregularity as to outline would drive your average foreman into profanity. Yet they are certainly divided into distinct classes, at least as to size and as to what the rooms contain. Some are apparently filled with nothing but air and have direct connection through the stoma with the outdoors. These are called intercellular spaces. Others, and these are most important, are filled mostly with the green coloring matter that gives the leaf its color.

    This substance is known as chlorophyll, its individual units as chloroplasts, or literally, chlorophyll bodies. Quite independently of these chlorophyll cells or rooms, or the intercellular spaces which correspond to halls, there are some large and many small tubes. These are the veins of the leaf and their finer branches and by their direct connection through the stem to the roots, serve as the ducts through which some of the raw materials are brought into the factory.