In a certain plant, a pair of leaves arise at each node and lie opposite to each other. Which of the following plants exhibits this type of leaf arrangement?

Step-by-step solution

The arrangement where a pair of leaves arise at each node and lie opposite to each other is defined as opposite phyllotaxy. According to NCERT, Calotropis and guava plants exhibit opposite phyllotaxy. Alstonia shows whorled phyllotaxy (more than two leaves arise at a node). Mustard and sunflower show alternate phyllotaxy (a single leaf arises at each node in an alternate manner). Answer: Calotropis