. Botany for agricultural students . Botany. 168 STEMS production, for a well branched tree can produce more flowers and fruit than one that is less branched, provided the food supply is sufficient. In plants used for forage, such as Clover and Alfalfa, the amount of hay produced by a plant depends largely upon the extent of branching. In some plants, as in the Pine shown in Figure I45, the stem system consists of a main axis and many lateral branches, forming what is known as the excur- rent type of stem. In others, , . as in the Elm shown in Figure , the main stem is divided into two or
. Botany for agricultural students . Botany. 168 STEMS production, for a well branched tree can produce more flowers and fruit than one that is less branched, provided the food supply is sufficient. In plants used for forage, such as Clover and Alfalfa, the amount of hay produced by a plant depends largely upon the extent of branching. In some plants, as in the Pine shown in Figure I45, the stem system consists of a main axis and many lateral branches, forming what is known as the excur- rent type of stem. In others, , . as in the Elm shown in Figure , the main stem is divided into two or more branches, which are soon lost in numerous branches, form- ing the deliquescent type of stem. Among fruit trees and forest trees, there is so much difference in habits of branch- ing that many kinds of trees can be identified by their branching habit. Work Done by Stems. — There are four important functions of stems. They support the aerial structures, conduct materials, make food, and serve as regions of storage. The supporting function consists in carrying the weight of the leaves, flowers, and fruit, and in elevating them to a position most favorable for performing their func- tions. There is strong competition among plants for light, and it is through the elongation of the stem that plants lift their leaves higher in the air and often escape the shade of neigh- boring plants. Some plants, such as the Grape, Poison Ivy, Morning Glory, Beans, and Peas, which have weak stems, secure better light by climbing a support, such as a wall, fence, or the stems of other Fig. 146. — Elm tree, showing deli- quescent type of 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 Martin, John N. (John Nathan), b. 1875. New York : John Wiley & Sons, Inc.
Size: 1272px × 1963px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
