Question

Number of orthostichies present in opposite and decussate phyllotaxy is

• A. Two
• B. Four
• C. One
• D. Three

Answer 1

The correct option is A Two

Phyllotaxy is the arrangement of the leaves on the stem. It is of three types, alternate, opposite and whorled. In opposite phyllotaxy, pair of leaves are present in opposite direction at each node. It is further divided into decussate and superposed. In decussate phyllotaxy, two successive pairs of leaves occur perpendicular to each other. Orthostichy is the row of leaves along the stem. All the leaves lie in a fixed number of orthostichies. Decussate and opposite phyllotaxy has 2 orthostichies. Example include Catharanthus roseus. In superposed phyllotaxy, the pairs of leaves are in the same plane. For example, Combretum.

Thus, the correct answer is 'Two.'