Based on its stimulus, the movements in plant are grouped into three.
1. Autonomic Movement
Is a movement that isn’t caused by external stimulus.
Example.
a. The flowing movement of sytoplasm in cell.
b. The bending movement of leaf bud because of difference of growth velocity.
c. Movement that is shown by plant when grows such as the growth of root, stem, leaf, and flower.
2. Exogenous Movement
Is a plant movement that caused by external stimulus. According to directions of stimulus and direction of response to the stimulus, this movement is divided into 3, namely NASTY, TROPISM, and TAXIS.
a. Nastic movement: is a plant movement that its direction is not determined by stimulus but by the plant itself.
1. Photonasty: caused by stimulus of sunlight.
Example: the closing and opening of Mirabilis jalava at certain time when there is light, the blossom of sun flower.
2. Nictinasty: caused by dark condition or sleeping movement
Example: the closing of leaves of butterfly flower aat night, the closing of compound leaves in Leucaena glauca (petai cina) at night.
3. Thigmonasty: caused by stimulus of touch
Example: the closing of leaves od Mimosa pudica when touched.
4. Thermonasty: caused by temperature stimulus
Example: tulip flower will develop if suddenly gets temperature increment and close anymore if temperature decreases.
5. Complex Nasty: caused by severel factors altogether, i.e CO2 level, CA ions, temperature, sunlight, etc.
Example: the opening and closing of stomata.
b. Tropism: is a plant movement that its direction is influeced by stimulus.
1. Phototropism: caused by stimulus of sunlight.
Example: the tip of plant in a room will direction of incident light.
2. Geotropism: tropism movement that follows Earth gravitational force.
Example: the tip of root grows to the direction of gravitation (positive geotropism), the tip of stem grows upward leaving gravitational force (negative geotropism)
3. Chemotropism: caused by stimulus of chemical substance.
Example: the movement of root to food substance in soil (positive Chemotropism), the movement of root leaving poison (negative Chemotropism).
4. Thigmotropism: caused by stimulus of touch to harder thing.
Example: Tendril (sulur) that touches hard thing, it will happen contact and that tendril will twist the hard thing.
5. Hydrotropism: movement of plant root that is influenced by reservation of soil water.
c. Taxis: transfer movement of all body to stimulus that its direction is determined by the stimulus .
1. Phototaxis: caused by stimulus of sunlight.
Example: the movement of chlorophyll to the surface that gets light, movement of spore that has flagella to the light place.
2. Chemotaxis: caused by chemical stimulus.
Example: movement of spermatozoid of moss plant and fern to ovum that is found in archegonium attracted to the sugar or protein that is produced by archegonium
3. Hygroscopic Movement: caused by the influence of the chage of water level from its cells so happens nonhomogenous wrinkling.
Example:
a. The opening of sporangium in fern as the cause of the wrinkling of annulus cells.
