. Elementary botany . Botany. CHAPTER XIII THE DISPERSAL OF SEEDS, AND A SUMMARY WITH REGARD TO THE FLOWERS In one season a single plant, say a Foxglove, may produce thousands of seeds. If every one of these seeds is to be afforded an opportunity of developing into a mature plant, means must be pro- vided to enable the seeds to reach suitable spots at some distance from the mother-plant. The seeds of flowering plants are con- veyed through the air in the same manner as the pollen, in so far that they are either violently ejected { Bal- sam, Oxalis), or are carried by the wind { Dande-
. Elementary botany . Botany. CHAPTER XIII THE DISPERSAL OF SEEDS, AND A SUMMARY WITH REGARD TO THE FLOWERS In one season a single plant, say a Foxglove, may produce thousands of seeds. If every one of these seeds is to be afforded an opportunity of developing into a mature plant, means must be pro- vided to enable the seeds to reach suitable spots at some distance from the mother-plant. The seeds of flowering plants are con- veyed through the air in the same manner as the pollen, in so far that they are either violently ejected { Bal- sam, Oxalis), or are carried by the wind { Dande- lion), or borne by animals { Rose, Cherry, Galium). Explosive fruits are not common. The capsule of the Violet opens into three boat - shaped valves, each containing a double row of smoothly - polished seeds. The sides of the boat-shaped valves contract as they dry, and fling out the seeds. To understand this mechanism, we have only to remember the manner in which an orange-pip springs out when squeezed between two fingers. Dispersal by the wind. i'P. Fig. T2Q.—Right-hand figure is a vertical section of infructescence of Dandelion: br— involucre. Left-hand figure is a vertical sec- tion of a single fruit (achene) with a pappus 0^) on a long beak; ^£:=pericarp ; ^f=testa of^the seed; cf?^=cotyledons ; r= radicle. —To facilitate dispersal by the 95. 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 Groom, Percy, 1865-1931. London : G. Bell
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1898
