The Collaborative International Dictionary
Circumnutate \Cir`cum*nu"tate\, v. i. [Pref. circum- + nutate.] To pass through the stages of circumnutation.
Wiktionary
vb. (context botany English) to bend in a direction that is continuously moving in a horizontal direction
Usage examples of "circumnutate".
It has already been stated that the cotyledons of Phalaris and Avena, the plumules of Asparagus and the hypocotyls of Brassica, were likewise able to displace the same kind of sand, either whilst simply circumnutating or whilst bending towards a lateral light.
As the arched epicotyl, in whatever position it may be placed, bends quickly upwards through apogeotropism, and as the two legs tend at a very early age to separate from one another, as soon as they are relieved from the pressure of the surrounding earth, it was difficult to ascertain positively whether the epicotyl, whilst remaining arched, circumnutated.
As soon, however, as the direction of the circumnutating movement nearly coincides with that of the entering light, the plant bends in a straight course towards the light, if this is bright.
From the particulars above given, and remembering in the case of twining plants and of tendrils, how difficult it is not to mistake their bending to all points of the compass for true torsion, we are led to believe that the stems of this Ceratophyllum circumnutate, probably in the shape of narrow ellipses, each completed in about 26 h.
In this small reduction in length of the pulvinus of the rudimentary leaflets of Desmodium, we apparently have the proximate cause of their great and rapid circumnutating movement, in contrast with that of the almost rudimentary leaflets of the Mimosa.
The sheathlike cotyledons of the Gramineae circumnutate, that is, move to all sides, as plainly as do the hypocotyls or epicotyls of any dicotyledonous plants.
We shall hereafter meet with the same kind of movement in the joints of certain Gramineae, and it is probably common to many plants while circumnutating.
In some cases, as with the hypocotyls of Brassica, the leaves of Dionaea and the joints of the Gramineae, the circumnutating movement when viewed under the microscope is seen to consist of innumerable small oscillations.
THE circumnutating movements of the several parts or organs of a considerable number of seedling plants have been described in the last chapter.
Even the stems of seedlings before they have broken through the ground, as well as their buried radicles, circumnutate, as far as the pressure of the surrounding earth permits.
When we treat of the sleep and other movements of plants, many other cases of circumnutating stems will be incidentally given.
In looking at the diagrams, we should remember that the stems were always growing, so that in each case the circumnutating apex as it rose will have described a spire of some kind.
Therefore the cotyledons certainly circumnutated, though the chief movement was up and down in a vertical plane.
Now, if a plant of this kind were converted into one that slept, one side of one of the several ellipses which each leaf daily describes, would have to be greatly increased in length in the evening, until the leaf stood vertically, when it would go on circumnutating about the same spot.
Again, climbing plants whilst young circumnutate in the ordinary manner, but as soon as the stem has grown to a certain height, which is different for different species, it elongates rapidly, and now the amplitude of the circumnutating movement is immensely increased, evidently to favour the stem catching hold of a support.