How Do Flowers Spread Their Seeds? A Detailed Guide to Common Dispersal Methods

Fresh flowers are something people see often in daily life, and all kinds of flowers bloom everywhere. So how do flowers spread their seeds? Let's take a look together below.

1. Self-dispersal by the plant itself

Some plants can spread their seeds on their own, without relying on other dispersal agents. The fruit or seed itself has weight, and once ripe, the fruit or seed falls directly to the ground due to gravity, such as the velvety persimmon (Diospyros discolor) and the big-leafed planchonella (Palaquium formosanum); while some capsules and siliques, when the fruit ripens and splits open, produce an explosive force that flings the seeds outward, such as the Taiwan Michelia (Michelia compressa). Self-dispersed seeds have a limited dispersal distance, but some self-dispersed seeds, after falling to the ground, undergo a secondary dispersal phenomenon, with birds, ants and mammals all being possible secondary dispersers.

2. Dispersal by wind

Some seeds grow appendages shaped like wings or feathers, and ride the wind to fly. Seeds with feathery appendages are mostly herbaceous plants, such as the youngia (Youngia japonica) of the Asteraceae family, while woody plants include the willow and the kapok. In addition, some tiny seeds have a relatively large surface area compared to their weight, so the seeds can drift with the wind, like the seeds of the orchid family. The achene of the dandelion, a plant of the Asteraceae family, spreads its pappus when ripe, like a parachute, drifting with the wind and scattering the seeds far away.

3. Dispersal by water

Seeds dispersed by water have a waxy surface that does not absorb water (such as the water lily), fruit skins containing air chambers, and a specific gravity lower than water, so they can float on the water surface and be dispersed via streams or ocean currents. The seed coats of such seeds often have a thick fibrous layer that prevents the seeds from rotting or sinking due to soaking and water absorption. Seaside plants, such as the box fruit tree (Barringtonia asiatica), the sea trumpet (Hernandia nymphaeifolia) and the tropical almond (Terminalia catappa), have typical seeds dispersed by water.

After the fruits and seeds of plants ripen, they generally rely on wind, water currents and animals for dispersal. Seeds or fruits dispersed by wind are all very light and delicate in structure. For example, the round wings around the fruit of the elm and the double wings of the maple are both fairly well adapted to wind dispersal.

4. Dispersal by humans or animals

1. Bird dispersal: Seeds dispersed by birds are mostly fleshy fruits, such as berries, drupes and syconia. Birds peck at the seeds of plants of the Lauraceae family and then spit the seeds out. After the fruit is eaten, the seeds pass through the digestive tract and are excreted at random. Plants that rely on birds to disperse their seeds are a relatively advanced group, because the distance over which birds disperse seeds is the farthest of all methods.

2. Insect dispersal: Pollen is used to attract insects to feed, thereby achieving dispersal.

3. Animal dispersal: Some mammals are relatively large in size and have large food requirements, so they choose some large fruits. For example, the macaque likes to eat the fruits of the velvety persimmon and the banana, and also helps these plants to disperse.

Flowers have quite a few dispersal methods, and different flowers disperse in different ways, which must be determined according to the actual variety.