When spring comes, the flowers bloom, but the careful people will find that some plants, although they have opened the flowers of a tree, are bare, have no leaves, and say “green leaves with red flowers”. So why do some plants have a “flowers without leaves” scene?
The first flowering leaves are important flowering characteristics of some plants. They are often found in woody plants of the family Rosaceae and Magnoliaceae, such as magnolia, wax plum, bauhinia, and spring jasmine. So why do some plants first bloom after the leaves, some plants first leaves the flowers, and some plants grow flowers and leaves at the same time?
There are three kinds of buds in plants: leaf buds, flower buds and mixed buds. The leaf buds eventually develop into shoots; the flower buds develop into flowers or inflorescences; while the mixed buds develop into long leaves and flowering branches, and the mixed buds contain leaf primordia and axillary bud primordia, as well as floral primordia. In terms of appearance, the mixed buds and flower buds are round and thick because of the embryos containing flowers or inflorescences, while the appearance of the leaf buds is relatively thin and slender. These buds are usually formed in the fall of the previous year. Over the winter, when the spring is over, the buds of each part will grow slowly. Whether they bloom first or first leaves are closely related to their requirements for the environment and temperature.
Plants that first bloom after the leaves, such as magnolia, require less temperature for flower bud growth, while leaf buds require higher temperatures. In the early spring, although the temperature gradually rises, there is still some cold, but it is enough to meet the needs of flower bud growth, but it can not meet the growth needs of leaf buds, so the leaf buds are still lurking, and the flower buds are developed one step at a time, forming the phenomenon of long leaves after flowering. When the flowers are gone, the temperature rises and the branches begin to reveal a piece of green leaves.
On the contrary, plants with first-leaf flowers, such as Acacia, have higher temperature requirements for flower bud growth than leaf buds, so leaf buds develop earlier, before the blooms, early with green trees; and those with leaf buds and flower buds Plants with similar requirements, such as weeping willows, will develop at the same time, forming a scene where flowers and leaves are open at the same time, as well as sea otters, which are also open at the same time.
In addition to the above reasons, there is also a view that the long leaves are first to promote the spread of pollen. For plants, pollination and reproduction are eternal wars. Most of the wind-flower flowers are “leaf-leaf-flowering” plants. For wind-flowered flowers, “flowering first” can also avoid leaf interference, and pollen is more easily blown by wind to other plants to achieve pollination.
Flowers and leaves are important organs of plants. When flowers are open, they have their own laws, and it is their difference that makes spring more colorful.