Mutous leaf arrangement: features and examples
Each of us noticed that leaves on plantsare located in a certain way. Biologists call this phenomenon phyllotaxis. From our article you will learn what a whorled leaf is and which plants in nature it meets.
Types of phyllotaxis
In apple and dog rose from the node only one leavessheet. The others are spirally relative to each other. This kind of phyllotaxis occurs in plants of the Umbilical, Cereal, Birch and Bukotsvetny families. It is called regular or spiral.
With the opposite phyllotaxis, there are two sheets in the node that are opposite each other. Examples of such plants are sage, mint, motherwort, rosemary, basil, lemon balm.
A whorled leaf arrangement: examples of plants and features
But plants with whorled phyllotaxis are not found in nature so often. At such species several leaves develop on one node at once.
The annular leaf arrangement (also calledwhorl) is considered the most beneficial for effective absorption of sunlight. In this case, the leaves practically do not shade each other. At the same time, their total area is much larger than that of the plant itself. As examples of plants with annular leaf arrangement, representatives of families Melantievye, Kutrovye, and also the genus Vodkrasovye can be cited.
Longline categories
The leaves located on different parts of the shoot vary morphologically and functionally from each other. According to these characteristics, they can be grouped into three groups:
- The grass-roots perform the function of protecting and storing nutrients. Develop at the bottom of the sheet. First have a white color, but over time the shade changes to brown or black.
- Median - photosynthetic leaves of green color with large plates. Develop in the middle part of the shoot.
- Horse - leaves located in the inflorescence area. They are underdeveloped, weakly divided. Their green color serves not for photosynthesis, but for attracting insects.
A whorled leaf arrangement makes it possibleeach plate to make the most of light. If the leaves grow in a horizontal or vertical plane on petioles of unequal height, the so-called mosaic is formed. It can be observed in plants with various phyllotaxis, including whorled.
Which plants have a whorl?
Several sheets in one site often develop inconiferous plants. This juniper, spruce, pine, cypress. Their leaves have an acicular shape and are called needles. This structure prevents excessive loss of moisture in the cold season. But for the implementation of photosynthesis needles should be located "bundles".
A whorled list is typical formany ornamental plants. It can be found in lilies and oleander. Their leaves have a rich green color and a wax coating, which makes these plants visually more attractive.
Examples of species with a whorled leafserves and horsetail field. It belongs to a group of higher spore plants. Moreover, the function of photosynthesis is performed only by the summer shoot, in the rosettes of which thin wedge-shaped leaves develop.
Elodea - a typical example of an aquatic plant with whorledphyllotaxis. In each node of the shoot, three leaves with a round oblong plate develop. They are transparent, bright green, located on long shoots. This structure makes the Elodie a real decoration of aquariums and reservoirs.
So, the ringed or whorled leaf arrangement,examples of which we considered in the article, is characterized by the presence in one node of several plates. In this case, they do not obscure each other, promoting the efficient process of photosynthesis.
