. Botany for young people and common schools. How plants grow, a simple introduction to structural botany. With a popular flora, or an arrangement and description of common plants, both wild and cultivated. Botany. 28 HOW PLANTS GROW YEAR AFTER YEAR. tliey must liave, in order to bear leaves; for leaves do not grow on roots. But "what stem they make is so very short-jointed that it rises hardly any ; so that the leaves seem to spring from the top of the root, and all spread out in a cluster close to the ground. As the plant grows, it merely sends out more and more branches of the root int
. Botany for young people and common schools. How plants grow, a simple introduction to structural botany. With a popular flora, or an arrangement and description of common plants, both wild and cultivated. Botany. 28 HOW PLANTS GROW YEAR AFTER YEAR. tliey must liave, in order to bear leaves; for leaves do not grow on roots. But "what stem they make is so very short-jointed that it rises hardly any ; so that the leaves seem to spring from the top of the root, and all spread out in a cluster close to the ground. As the plant grows, it merely sends out more and more branches of the root into the foil beneath, and adds more leaves to the cluster just above, close to the surface of the warm ground, and well exposed to the light and heat of the sun. Thus consisting of its two working organs only, — root and leaves, — the young biennial sets vigorously to work. The moisture and air which the leaves take in from the atmo-^phere, and all that the roots take from the soil, are digested or changed into vegetable matter by the foliage while exposed to sunshine; and all that is not wanted by the leaves themselves is generally carried down into the body of the root and stored up there for next year's use. So the biennial root becomes large and heavy, being a storehouse of nourishing matter, which man and animals are glad to use for food. In it, in the form of starch, sugar, mucilage, and in other nourishing and savory products, the plant (expending nothing in flowers or in show) has laid up the avails of its whole summer's work. For what purpose ? This plainly appears when the next season's growth begins. Then, fed by this great stock of nourishment, a stem shoots forth rapidly and strongly, divides into branches, bears flowers abundantly, and ripens seeds, almost wholly at the expense of the nourishment accumulated in the root, which is now light, empty, and dead; and so is the whole plant by the time the seeds are ripe. 71. By stopping the flowering, biennials can som
Size: 1221px × 2047px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., c1858bookdecade1860bookcentury1800bookauthorgrayasa18101888boo
