How is alternate phylllotaxis defined?
Three or more leaves per node, the angle of divergence varying
One leaf per node, 137.5 degree angle of divergence between leaves
One leaf per node, and the leaves positioned 180 degrees from each other
Two leaves per node, 90 degrees angle of divergence between leaves
Two leaves per node 45 degree angle of divergence between leaves
Two leaves per node, the angle of divergence varying.
Alternate phyllotaxis refers to the arrangement of leaves or other plant structures along a stem or branch. It can be defined in different ways depending on the number of leaves per node and the angle of divergence between them. Here are the definitions for different types of alternate phyllotaxis:
1. Three or more leaves per node, the angle of divergence varying: In this type of alternate phyllotaxis, three or more leaves are attached at each node, and the angle between leaves can vary. This means that the leaves are not directly opposite each other, but alternate around the stem or branch.
2. One leaf per node, 137.5 degree angle of divergence between leaves: This type of alternate phyllotaxis is known as the "golden angle" arrangement. Each leaf is attached at a different node, and the angle between consecutive leaves is approximately 137.5 degrees. This angle is derived from the golden ratio, a mathematical concept often found in natural patterns.
3. One leaf per node, and the leaves positioned 180 degrees from each other: In this type of alternate phyllotaxis, each node carries only one leaf, and the leaves are positioned directly opposite each other, creating an arrangement of 180 degrees between them.
4. Two leaves per node, 90 degrees angle of divergence between leaves: This type of alternate phyllotaxis is known as the opposite decussate arrangement. At each node, two leaves are attached at right angles (90 degrees) to each other, forming an "X" shape.
5. Two leaves per node, 45 degrees angle of divergence between leaves: This type of alternate phyllotaxis is known as the alternate decussate arrangement. At each node, two leaves are attached at an angle of 45 degrees to each other, forming a zigzag pattern along the stem or branch.
These different types of alternate phyllotaxis represent variations in the arrangement and angles between leaves, allowing plants to optimize their exposure to light and efficient use of space.
Alternate phyllotaxis refers to the arrangement of leaves on a stem or branch of a plant. It is defined by the number of leaves per node and the angle of divergence between them. Here are the definitions for the different types of alternate phyllotaxis mentioned in your question:
1. Three or more leaves per node, the angle of divergence varying:
In this arrangement, each node on the stem or branch has three or more leaves, and the angle between each leaf can vary.
2. One leaf per node, 137.5 degree angle of divergence between leaves:
This type of phyllotaxis is known as "Fibonacci phyllotaxis." It is characterized by one leaf per node, and the angle between each leaf is approximately 137.5 degrees. This angle is closely related to the golden ratio, a mathematical concept often found in nature.
3. One leaf per node, and the leaves positioned 180 degrees from each other:
This is called "opposite phyllotaxis." Each node on the stem or branch has only one leaf, and the leaves are arranged directly across from each other, creating a 180-degree angle between them.
4. Two leaves per node, 90 degrees angle of divergence between leaves:
This type of phyllotaxis is referred to as "decussate phyllotaxis." It involves two leaves per node, positioned opposite each other at a 90-degree angle.
5. Two leaves per node, 45 degrees angle of divergence between leaves:
This is known as "whorled phyllotaxis." Each node on the stem or branch has two leaves, and they are arranged in a circular pattern with a 45-degree angle of divergence between them.
These different arrangements of leaves are just a few examples of the various phyllotaxis patterns found in nature. It is worth noting that phyllotaxis can vary not only between different plant species but also within the same species or even within a single plant.