| 释义 |
circumnutation Bot.|ˌsɜːkəmnjuːˈteɪʃən|
[n. of action from prec.: see nutation.]
A movement characteristic of growing plants, due to increased growth at different points round the axis in succession, whereby the growing part (e.g. the apex of a stem) describes a more or less circular spiral path. (See nutation.)
[1875Bennett & Dyer tr. Sachs' Bot. iii. iv. 766 Curvatures..caused by the unequal growth of different sides of an organ may be called Nutations..It is common for the apices of erect stems above the curved growing part to move round in a circle or ellipse, the region of most active growth moving gradually, as it were, round the axis. This kind of nutation may be termed a Revolving Nutation.] 1880Darwin Movem. Pl. 1 This movement has been called by Sachs ‘revolving nutation’; but we have found it much more convenient to use the terms circumnutation and circumnutate. 1882Garden 14 Jan. 32/3 The method of climbing by twiners was a modification of the property of ‘circumnutation’.
So circumˈnutatory a., pertaining to circumnutation.
1880Athenæum 18 Dec. 817/2 The movements of climbing plants..are modifications of this circumnutatory tendency. |