Leaf is one part of plant, of course, besides stems and roots. In general, leaves are green because they contain chlorophyll, but there is also leaves of plants that are yellow and red etc.
There is chlorophyll in leaves which serves as a catcher of sunlight energy used for photosynthesis. Leaves are the most important part for plant because the plant is autotroph obligate organism; to carry out its life, plant must supply energy through change of sunlight energy into chemical energy (photosynthesis).
In fact, there are many shapes of leaves, but generally leaves are in the shape of thin and thick strands. The basic shape is round, with some variance of finger shape, elliptical and elongated. There are also spiny leaves, generally live in dry areas, such as cactus, succulent, Xerophyte, etc. The thistles do not require photosynthesis because they experience function transition from energy storage into water storage.
The green color in leaves is derived from chlorophyll. Chlorophyll is a pigment compound that is instrumental in the process of leaf photosynthesis. There are also other pigments such as carotenoids (orange), xanthophyll (yellow), anthocyanin (red, blue, purple, depending on the degree of acidity).
Functions of Leaves
1. Place of photosynthesis
At dicotyledonous plants, the photosynthesis is in the palisade parenchyma tissue, whereas for monocot plants, photosynthesis occurs in spongy tissue.
2. Respiratory organ
Respiratory organ in leaf is stomata, which serves as the organ of respiration
3. Place of transpiration
Transpiration is the release of water in the form of water vapor through the stomata and the cuticle to the free air
4. Place of Guttation
Guttation is the process of water release in liquid form on the leaf tissue.
5. Tools of vegetative proliferation
It is proliferation that occurs in leaves. Here shoots of plants grow on the leaves.
