| 单词 | positive heliotropism |
| 释义 | > as lemmaspositive heliotropism The property, exhibited by growing parts of plants, of bending or turning in a particular manner under the influence of light. The most usual case (to which some restrict the term) is that of bending towards the light ( positive heliotropism); that of bending away from it is distinguished as negative heliotropism or apheliotropism n.; that of taking a direction at right angles to it, as transverse heliotropism or diaheliotropism n. ΘΚΠ the world > plants > part of plant > growth, movement, or curvature of parts > [noun] > tropisms heliotropism1854 geotropism1873 apheliotropism1880 apogeotropism1880 nyctitropism1880 paraheliotropism1881 hydrotropism1882 selenotropism1883 selenotropy1883 rheotropism1884 orthotropism1885 plagiotropism1886 geotropy1888 haptotropism1888 aerotropism1889 phototropy1892 autotropism1897 plagiotropy1898 thermotropism1898 traumatropism1898 phototropism1899 gravitropism1969 1854 R. G. Mayne Expos. Lexicon Med. Sci. (1860) Heliotropismus, term for that faculty by which certain plants constantly turn their flowers to the sun: heliotropism. 1875 A. W. Bennett & W. T. T. Dyer tr. J. von Sachs Text-bk. Bot. 677 Both positive and negative heliotropism occur not only in organs containing chlorophyll, but also in those that are colourless. 1875 A. W. Bennett & W. T. T. Dyer tr. J. von Sachs Text-bk. Bot. 775 The positive heliotropism of twining internodes is generally feeble. 1880 Nature 11 Mar. 438/2 The Electric Light..producing heliotropism in plants exposed to it. 1880 C. Darwin & F. Darwin Power of Movement in Plants 5 Authors speak of positive and negative heliotropism..but it is much more convenient to confine the word heliotropism to bending towards the light. < as lemmas |
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