Phylotaxis
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The document discusses the two types of phyllotaxis, which is the arrangement of leaves on a stem. Spiral phyllotaxis has leaves arranged singly at each node in a spiral pattern, as seen in mustard and sunflower. Cyclic phyllotaxis has two or more leaves at each node. There are four types of cyclic phyllotaxis: opposite, opposite and superposed, opposite and decussate, and whorled/verticillate. Examples of each type are provided.
Phylotaxis
- 2. What is Phyllotaxis? Explain with diagrams • The arrangement of the leaf on the stem is called phyllotaxis. The object of the phyllotaxis is to avoid over crowding. So that all leaves get maximum light for photosynthesis. • There are two types of phyllotaxis: • a) Spiral • b) Cyclic
- 3. Two types of phyllotaxis: a) Spiral phyllotaxis: When the leaves are present singly on each node, such an arrangement of leaves is called spiral. And the leaves are said to be alternate as in mustard, sunflower etc. b) Cyclic phyllotaxis: If two or more leaves are present at each node such an arrangement of leaves is called cyclic.
- 4. Types of cyclic phyllotaxis: • Opposite : If only two leaves arise at each node , they are described as opposite. • Opposite and superposed; If the opposite leaves borne at any one node, are parallel to those of the upper node, they are said to be opposite and superposed. E.g. Jaman.
- 5. Types of cyclic phyllotaxis: • Opposite and Decussate: If opposite leaves at any one node are at right angles to those at the upper or lower node, they are described as Opposite and decussate . e.g. Mint, Niazbo, Calotropis. • Whorled or Verticillate : If more than two leaves are present at each node and are arranged in a circle around it , they are said to be whorled or verticillate as in Oleander
- 6. Types of cyclic phyllotaxis: