What is "petiole"

Usage examples of "petiole".

Although the main petiole is continually and rapidly describing small ellipses during the day, yet after the great nocturnal rising movement has commenced, if dots are made every 2 or 3 minutes, as was done for an hour between 9.

The leaflets are small, of a paler green and more tender consistence than the foliaceous petioles.

In some few cases this is effected by the rotation of the blade, the petiole not being either raised or lowered to any considerable extent.

The fact of so many organs of different kinds--hypocotyls and epicotyls, the petioles of some cotyledons and of some first leaves, the cotyledons of the onion, the rachis of some ferns, and some flowerstems--being all arched whilst they break through the ground, shows how just are Dr.

Four hypocotyls were surrounded close beneath their petioles with strips of thin tinfoil, .

As a little loop of fine thread hung on a tendril or on the petiole of a leafclimbing plant, causes it to bend, we thought that any small hard object affixed to the tip of a radicle, freely suspended and growing in damp air, might cause it to bend, if it were sensitive, and yet would not offer any mechanical resistance to its growth.

When the leaflets sink vertically down at night and the petioles rise, as often occurs, it is certain that the upward movement of the latter does not aid the leaflets in placing themselves in their proper position at night, for they have to move through a greater angular space than would otherwise have been necessary.

Here then the arching of the plumule plays the same part as in the case of the petioles of the Delphinium.

The bilobed leaf appears also to be rather larger and somewhat broader, with the pedicel by which it is attached to the upper end of the petiole a little longer.

After a few additional days the illdefined zone of cells becomes distinct, and although it does not extend across the whole width of the petiole, and although the cells are of a green colour from containing chlorophyll, yet they certainly constitute a pulvinus, which as we shall presently see, acts as one.

As the pulvinus is so indistinct at first, the movement probably does not then depend on the expansion of its cells, but on periodically unequal growth in the petiole.

We learn from these two cases of Lotus and Oxalis, that the development of a pulvinus follows from the growth of the cells over a small defined space of the petiole being almost arrested at an early age.

It was afterwards ascertained that the above movement was compounded of the circumnutation of the stem on a small scale, of the main petiole which moved most, and of the subpetiole of the terminal leaflet.

The main petiole of a leaf having been secured to a stick, close to the base of the subpetiole of the terminal leaflet, the latter described two small ellipses between 10.

The movement of the terminal leaflet by means of its subpetiole or pulvinus is quite as rapid, or even more so, than that of the main petiole, and has much greater amplitude.