Leaves turn brown in autumn due to the deterioration of chlorophyll, the green pigment found in all leaves responsible for absorbing light for photosynthesis, explains the U.S. Forest Service. Intrinsically, the trees are aware that approaching winter weather will not offer enough sunlight or water to sustain their leaves, so the leaves fall off and the trees go dormant.
When tree leaves turn brown and fall off, the tree is in the process of suspending its functions for the winter. When autumn sets in, the days grow shorter and the amount of sunlight the trees receive is diminished. Additionally, due to a lack of rain in the winter months, drought has an effect on a tree being able to sustain its leaves. This combination of lack of sunlight and water leads to the halt of vein activity within the leaves. Ordinarily, these veins are responsible for pumping nutrients throughout the tree. When there are no nutrients to pump, the veins shut down. When this occurs, the leaf eventually dies and falls from the tree. Brown leaves are seen closer to winter and follow the warm foliage of autumn. When they litter the ground at the base of the trees, they act as an all-natural fertilizer. When spring comes back around, those leaves decay, replenish the tree and aid in leaf regrowth.Learn More
Traditionally, lysosomes were thought to exist only in animal cells, but contemporary biologists and botanists have found lysosomes in some plants. However, whether these plant organelles are truly considered lysosomes is still under debate.Full Answer >
Germination takes place in three steps or stages and takes the young seed from a dormant state to the very beginning stage of growing as a seedling. Germination takes place in plants, flowers and trees: this process is to members of the plant family what metamorphosis is to insects such as moths and butterflies. The process requires several critical ingredients to begin, including water, sunlight and nutrients.Full Answer >
Guava leaves are used primarily to make herbal tea, certain cosmetic and beauty products, and for medicines. Guava leaves, like the fruits and other parts of the plant, are considered safe for human consumption. The leaves of these tropical plants contain an abundance of minerals and antioxidants, which makes them suitable for adding to medicines, teas and cosmetic products.Full Answer >
The most common identifying characteristics of a black walnut tree are found in its leaves, bark, twigs and nuts. Oval, sharp-pointed leaves with indented edges alternate on the branches, with the largest leaves toward the center. The black or gray-brown bark shows heavy furrows and twigs are hollow inside.Full Answer >