Definitions / Explanation :
$(i)$ Phylloclade
$(ii)$ Aestivation

(N/A) $(i)$ In some plants,the petiole expands,becomes green,and synthesizes food. This modified structure is called a phyllode (often confused with phylloclade,but in the context of $NCERT$ morphology,the flattened petiole is a phyllode). $A$ phylloclade is a green,flattened or cylindrical stem that performs photosynthesis,commonly seen in Opuntia.
$(ii)$ The mode of arrangement of sepals or petals in a floral bud with respect to the other members of the same whorl is known as aestivation.