Similarities and differences between leaves of different plants
Leaves of different plants can vary greatly in form, appearance, location on the stem. Despite this, they have a lot in common: most of the leaves are green and consist of the leaf blade and petiole that connects the leaf to the stalk.
Petiolate and sessile leaves
The leaves growing on stalks, called "stalked". They are available in Apple, cherry, birch, maple. The leaves of some other plants such as aloe, flax, chicory, wheat, no petioles, and are attached to the stem they are the bases of the leaf blades. They are called "sessile".
Leaf shape as an adaptation to environmental conditions
The shape of the leaves can be oval, rounded, needle-like (needles), heart-shaped, etc. most Often this form is an adaptation to specific environmental conditions: for example, needle-like leaves of conifers reduces the leaf surface and protect the plant from excessive evaporation and loss of moisture. Vary can and the edges of the leaves: for example, a scalloped edge in Apple, serrate from aspen, smooth-edged images.
The leaves are simple and complex: what is the difference?
Botanists divide the sheets into simple and complex. Simple leaves, found in birch, oak, maple, cherry and other plants, are composed of one leaf blade. Compound leaves are represented by several leaf blades, connected by small stalks from a common petiole. They can be observed in a mountain ash, ash, acacia, rose, bean, chestnut and many others.
Types of venation of leaf
Leaf blade penetrated the conducting bundles of the veins. These veins form a solid frame sheet and carried out solutions of the nutrients.
If the veins are arranged in parallel, talking about parallel venation of the leaf. It is typical of many monocotyledonous plants of rye, wheat, onions, barley and others. Also characteristic of monocots is the arc venation when "parallelism" is broken, and the leaves are slightly curved arcuate (Lily of the valley, aspidistra, dicotyledonous plant – plantain).
In the case of reticulated venation the veins branch repeatedly and form a network. Most typically such for the venation of dicotyledonous plants. But there are exceptions: crow's eye – a monocotyledonous plant, and the veins in its leaves are located in the network view.