The leaves on the shoot are not at all random. Their attachment to the axis of the aerial part of the plant occurs only in certain places, which are called nodes, and has its own patterns. In our article, we will look at what an opposite leaf arrangement is.
Types of leaf arrangement
Leaf arrangement, or phyllotaxis, is a certain order of attachment of leaves to the stem. This feature is an important systematic feature. There are three main types: alternate (spiral), whorled (annulate) and opposite leaf arrangement.
In the first case, only one leaf leaves the node. Relative to each other, they are arranged in a spiral. Examples of such plants are pear, rosehip, wheat and peach. With a whorled type, more than two leaves depart from the node. Such a leaf arrangement can be observed in pine, crow's eye, cypress, elodea.
Features of opposite leaf arrangement
The opposite type is characterized by the presence of two leaves in a node. At the same time, they are located opposite each other. As a result, a kind ofmosaic that allows you to make the most of the sunlight. Opposite leaf arrangement is considered a special case of whorled. Two plates are located in one node in such a way that their medians are in a single vertical plane.
Which plants have opposite leaf arrangement
Naturally, the order of the leaves on the stem is not the only feature that determines the systematic position of the plant. But it is always used when describing species. So, the opposite leaf arrangement is typical for representatives of the Honeysuckle, Lamiaceae and Clove families.
The first of these includes viburnum, elderberry, honeysuckle, musky grass, three-stone, snowberry, linnaeus, diervilla. The mint, basil, sage, lemon balm, thyme, oregano, savory are part of the Lamiaceae family, or Lamiaceae. Most of them are herbaceous plants. This family received the name Lamiaceae because of the appearance of the flowers. They look like an open mouth.
Most representatives of the Clove family are also herbaceous. They are used as fodder and ornamental crops, and some have been used in medicine. This is Smolevka, soapwort, dawn, toritsa, drowsiness.
So, with opposite leaf arrangement, two plates are located opposite each other at the nodes. This feature of the structure is characteristic of clove, honeysuckle and lamb plants.
