Leaf

The main photosynthetic organ of a plant, with the gases being used and produced in this process, as well as that of respiration, using stomata as a means of entry and exit to and from the leaf.

The internal features of a leaf will also contain two main transportation cells, the phloem and xylem. With organic material, for example carbohydrates, being produced by photosynthesis this needs to be transported to places where it can be utilised, and this is carried out by the phloem. The xylem helps transport water and nutrients for leaf growth, and also to help keep the plant and leaves cool as part of the transpiration process.

A grass leaf is a composite term which consists of the leaf blade (which is often called the leaf, but that is technically incorrect), as well as the ligule and auricle, where it is present on some grasses.

A leaf on some plants, such as trees, might consist of a petiole which joins the leaf with a stem, stipules that are small growths at the base of a petiole, as well as the lamina (typically identified as the leaf), which may have noticeable veins, which branch off from a mid-rib.