. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. MORE ABOUT POLLINATION 321 Sorrel (Oxalis) and touch-me-not (Tmpatiens) are ex- amples of plants which sometimes produce cleistogamous flowers. Low temperature is believed to be the principal cause which induces their pro- duction. Lamium, one of the mint family, produces cleistog- amous flowers in spring and autumn, and open flowers in the Fig. 141. — One of the milkworts {Polygala polygama), bearing both aerial open flowers and subterra- nean cl
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. MORE ABOUT POLLINATION 321 Sorrel (Oxalis) and touch-me-not (Tmpatiens) are ex- amples of plants which sometimes produce cleistogamous flowers. Low temperature is believed to be the principal cause which induces their pro- duction. Lamium, one of the mint family, produces cleistog- amous flowers in spring and autumn, and open flowers in the Fig. 141. — One of the milkworts {Polygala polygama), bearing both aerial open flowers and subterra- nean cleistogamous flowers. The subterranean flowers are self-pol- linated and produce pods which contain many seeds. H. Which Kind of Pollina- tion is Better ? — The test of pollination is the quality of the progeny resulting from the seeds produced thereby. It is commonly believed that the progeny resulting from cross- pollination is in general bet- ter than that resulting from close-pollination. Numerous experiments, conducted through many years, tend to show this to be true. But there is something to be said in favor of the other method. In some plants, close-pollination has been shown to result in progeny of at least equal vigor with that resulting from cross-pollination. Tobacco, petunia, and California poppy are examples of this. It is evident that close-pollination is much simpler than cross-pollination. It does not require such elaborate structures. It does not involve any waste of pollen. (Some cleistogamous flowers have only one anther and only a few grains of pollen in that.) It is certain, not. 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 Coulter, John G. (John Gaylord), b. 1876. New York, American Book Co
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
