. Botany; principles and problems. Botany. REPRODUCTION 193 units of the pistil arc inoiphologically leaves; and that the earliest floral type was perfectly regular, with its various parts rather numerous and with no fusion whatever between circles or between inenil)ers of the same circle. Inflorescence.—T\ie arrangement of flowers on the plant is known as the inflorescence. The flowers may be solitary, arising from the ground, or singly in the axils of the leaves (Figs. 233. Fig. 107.—Wind-pollinated flowers of the alder {Alnus). The long catkins are groups of male flowers just ready to shed
. Botany; principles and problems. Botany. REPRODUCTION 193 units of the pistil arc inoiphologically leaves; and that the earliest floral type was perfectly regular, with its various parts rather numerous and with no fusion whatever between circles or between inenil)ers of the same circle. Inflorescence.—T\ie arrangement of flowers on the plant is known as the inflorescence. The flowers may be solitary, arising from the ground, or singly in the axils of the leaves (Figs. 233. Fig. 107.—Wind-pollinated flowers of the alder {Alnus). The long catkins are groups of male flowers just ready to shed their pollen. The smallest catkins are composed of female flowers, their stigmas ready to receive the pollen blown through the air. The woody cones of last year, which developed from the female catkins and have shed their seed, are also shown. and 240); or the leaves may be reduced to small bracts, the inter- nodes shortened, and the flowers thus grouped into definite clusters. Such clusters are of various types as to shape and arrangement, the commonest among them being the raceme (Fig. 234), spike, head (Fig. 236), umbel (Fig. 235), corymb, panicle, and cyme. Pollination.—The first step in the accomplishment of repro- duction is the transfer of pollen from the anthers to the stigma, a process known as pollination. At about the time the flower unfolds, the anthers open and hberate the pollen grains. In rare cases the stigma lies so close to the anthers that the pollen is. 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 Sinnott, Edmund Ware, 1888-. New York, McGraw-Hill
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1923
