Question

Parkinsonia is a good example of?
A. Phylloclade
B. Parachute mechanism
C. Phyllode
D. Winged fruit

Answer 1

The scientific name of it is Parkinsonia aculeata. It is a xerophyte. It belongs to the pea family. The leaves and stem are hairless whereas the petiole is flattened. It is basically a weed which has invaded Australia and is often called Australia's worst weed.

Complete answer:
As I mentioned that its petiole is flattened, by now you should be able to guess the answer. Let us look at the options one after the other. The first option is phylloclade which is a modification of the stem where the stem is reduced and performs the function of photosynthesis as leaves are not present. Examples include Opuntia. Parkinsonia has leaves and no such stem modification is seen and hence you can rule out the first option. The second option is the parachute mechanism where the seeds are dispersed by wind due to hairy pappus and hence the name parachute. This is the characteristic feature of Compositae, hence this is an incorrect option. Next, phyllode which is a modified petiole and looks similar to a leaf which is found in Parkinsonia. The last option winged fruits are the type of fruits where a flattened wing develops from the ovary wall and is found in a dry fruit called Samara.

Hence, the correct option is C.

Note:
Different parts of the plant like leaves, stem, roots show various modifications so as to adapt to the environmental stress. One such modification is phyllode. Phylloclade and phyllode are completely different. Phylloclade is the stem modification which performs the functions of leaf whereas phyllode is a modified petiole to reduce the transpiration through leaves.