. Botany for high schools. Botany. TYPES AND KINDS OF STEMS 43 :alled stemless " plants, and this is the meaning of acaiilescent plants. The plant appears to be composed only of root and leaves. But there is a very short section of the stem, difficult to define its limits, between the root and leaves and to which they are attached. It is at the crown of the root, and for this reason such a stem may be called a crown stem. Many biennials have crown stems. The beet, turnip, parsnip and carrot are also examples, but because of the large, fleshy root of these plants they are some- times calle
. Botany for high schools. Botany. TYPES AND KINDS OF STEMS 43 :alled stemless " plants, and this is the meaning of acaiilescent plants. The plant appears to be composed only of root and leaves. But there is a very short section of the stem, difficult to define its limits, between the root and leaves and to which they are attached. It is at the crown of the root, and for this reason such a stem may be called a crown stem. Many biennials have crown stems. The beet, turnip, parsnip and carrot are also examples, but because of the large, fleshy root of these plants they are some- times called crown tubers. The crown stem of the dandelion is perennial and bears the foliage leaves. But each year it develops one or more flower stems which die down after the seed ripens. In the fleshy roots mentioned above, during the second year a tall leafy stem is developed which bears flowers and seed. The fleshy roots are reservoirs for the storage of food material (see Chapter II). j SPECIALIZED STEMS. I 73. Bulbs—A bulb is a specialized shoot with a very short stem which is covered with numerous overlapping thick leaves, as in the onion, hyacinth, lily, tulip, etc. The onion is made up largely of broad, thick, short, fleshy leaves, or the leaf bases, which overlap very closely and make a more or less flattened circular or oval body. The outer leaves Section of onion "bulb," showing thick fleshy leaves. are usually dead, thin, papery and brown. A longitudinal section through the middle shows well the thickness and relation of the leaves. At the lower end can be seen the flattened very short stem to the upper surface of which the leaves are attached, while the roots extend from the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Atkinson, George Francis, 1854-1918. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
