Among the following plant species, which one demonstrates whorled phyllotaxy?

Alstonia

The correct answer is Option (2) -Alstonia

Phyllotaxy is the pattern of arrangement of leaves on the stem or branch. This 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.