leaf
Leaves are vegetative organs of higher plants, and lateral leaves developed from plants. Leaves contain chloroplasts, which are the main sites for plant photosynthesis. At the same time, the plant's evapotranspiration is achieved through the pores of the leaves. Leaves appear only on the real stems, that is, only the vascular plants have leaves. All higher plants such as ferns, gymnosperms and angiosperms have leaves. In contrast, bryophytes, algae, fungi and lichens have no leaves. In these flat bodies (Thallus) can only be found similar to the structure of leaves, but only as analogues (Analoga). But some people think that the above-mentioned extension of the leaves is only narrow. Broadly defined leaves should refer to all organizational structures that are capable of photosynthesis. But there are some of the stems in order not to let the water is evaporated, and evolved out like a cactus-like needle-like leaves. ...