How do flowers spread seeds?

Flowers spread seeds in many ways, and some activities of people and animals can help flowers spread seeds; natural factors such as water and wind can help some flowers spread seeds; some plants will rely on their own special mechanisms to spread seeds.

I. self-transmission

The so-called self-transmission is spread by the plant itself, and does not rely on other media. The fruit or seed has its own weight, and after ripening, the fruit or seed will fall directly to the ground due to gravity, such as persimmon and Camellia oleifera, while some capsules and pods will produce the force of ejection when the fruit is ripe and crack, ejecting the seed, such as black stone. The spread distance of self-transmitted seeds is limited, but some self-transmitted seeds will have secondary transmission after falling to the ground. Birds, ants and mammals are all possible secondary disseminators.

2. Wind propagation

Some seeds grow into wings or feathery appendages and fly in the wind. Most of the seeds with feathery appendages are herbaceous plants, such as yellow quail of Compositae, and woody plants such as willow and kapok. In addition, some small seeds have a large relative ratio of surface area to weight, so that the seeds can drift away with the wind, like orchid seeds. The achene of the dandelion of the Compositae plant, the crown hair expands when ripe, like a parachute, fluttering in the wind, spreading the seeds far away.

III. Water transmission

Water-borne seeds have a waxy surface that does not stick to water (such as water lilies), and their peels contain air chambers and have a lower specific gravity than water, so they can float on the surface and spread through streams or ocean currents. The seed coat of such seeds is often rich in fiber, which can prevent the seeds from rotting or sinking by soaking or absorbing water. Seashore plants, such as chessboard feet, lotus leaves and olive kernels, have typical waterborne seeds.

When the fruits and seeds of plants are ripe, they are generally spread by wind, water and animals. Seeds or fruits spread by the wind are light in structure. For example, the round wings around the fruit of the elm and the wings of the maple are more suitable for wind transmission.

IV. Animal transmission

1. Birds: most of the seeds transmitted by birds are fleshy fruits, such as berries, drupes and cryptic fruits. Birds peck at the seeds of Lauraceae and spit them out. After the fruit is eaten, the seeds pass through the digestive tract and are excreted at will. Plants that rely on birds to spread seeds are a relatively advanced group, because birds spread seeds the farthest of all ways.

two。 Insect transmission: spread by letting insects feed on pollen.

3. Mammal transmission: most of the transmission of mammals belongs to medium to large fleshy or dried fruits. Generally speaking, mammals are relatively large in size and have large food requirements, so they will choose some large fruits. For example, macaques like to eat the fruits of hairy persimmons and plantains, which also help these plants spread.