Explain with suitable examples the different types of phyllotaxy.
Phyllotaxy is the pattern of arrangement of leaves on the stem or branch. It is usually of three types – alternate, opposite and whorled.
In alternate type of phyllotaxy, a single leaf arises at each node in alternate manner, as in china rose, mustard and sun flower plants. In opposite type, a pair of leaves arise at each node and lie opposite to each other as in Calotropis and guava plants. If more than two leaves arise at a node and form a whorl, it is called whorled, as in Alstonia.
Explanation
The answer is based on section 5.3.3 of the NCERT textbook. The definition of phyllotaxy is stated first, followed by the three types with their characteristic features and examples. Each type is clearly distinguished: alternate has one leaf per node, opposite has a pair of leaves per node, and whorled has more than two leaves per node forming a whorl.