. A textbook of botany for colleges and universities ... Botany. 676 ECOLOGY Land plants with little capacity for vegetative reproduction. — Many herbs with persistent primary roots { dock, dandelion, vervain) die down to the ground in autumn, appearing essentially stemless in winter. In reality there is a short thick stem which elongates and enlarges slightly each year; at first only one bud is formed, growing into a single leafy shoot, but, as the size increases, a number of buds are formed, growing into several leafy shoots. Such a perennial stem is known as multicipital (figs. 994-996,
. A textbook of botany for colleges and universities ... Botany. 676 ECOLOGY Land plants with little capacity for vegetative reproduction. — Many herbs with persistent primary roots { dock, dandelion, vervain) die down to the ground in autumn, appearing essentially stemless in winter. In reality there is a short thick stem which elongates and enlarges slightly each year; at first only one bud is formed, growing into a single leafy shoot, but, as the size increases, a number of buds are formed, growing into several leafy shoots. Such a perennial stem is known as multicipital (figs. 994-996, 716, 717). Plants with multicipital stems do not migrate, and vegetative reproduction is very hmited, on account of the lack of lateral ground stems with adventitious roots; new stem increments are as de- pendent as the old upon the persistent primary root. Annual and biennial herbs, many shrubs, and most trees have persistent primary roots and are without lateral ground stems bearing adventitious roots; like multicipital herbs, they have little or no capacity for vegetative repro- duction. While some trees exhibit propa- gation by roots (p. 505), others (as the linden and the redwood) produce suckers at the base, thus resembling multicipital herbs except in the persistence of the aerial stems; basal shoots of this sort, however, are of little reproductive sig- nificance. In various trees and shrubs, especially the willows, cuttings placed in the soil develop into new plants; repro- duction of this kind is rare in nature, though employed artificially in many plants. Of all the common trees the conifers have the least capacity for vege- tative reproduction, but a fallen Torreya tree develops adventitious roots and erect shoots along the trunk almost as readily as do the Fig. 993. — A plant of the dwarf ginseng (Panax trifolium), showing a corm or solid bulb (c); note the whorl of three palmately compound leaves and the umbel of pistillate flowers (n). Reproduction
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
