Question

An example of parasitic plant which is strictly epiphytic is
A) Cucusta
B) Viscum
C) Orobanche
D) Rafflesia

Answer 1

Hint: Epiphytes are also called air plants. They grow on the surface of the plants. They derive nutrients and moisture from the surroundings.

Complete Answer:
To solve this question, we must know about the parasitic plants and about epiphytes.
Parasitic plants are the plants which live on other plants (host) and derive their nutrition from the host. If the host dies, plants die too. For example Cucusta, Orobanche.
Epiphyte is a Greek word - Epi meaning upon and python meaning plants. They grow on the surface of the plants but do not derive nutrition from the host plant.
They grow harmlessly on the other plants for physical support but do not harm the host plant. Older plants will have more epiphytes. Epiphytic plants are not parasitic.
For example Viscum. It grows on the host plant but does not derive its food from the host. It can carry out its own photosynthesis.
Rafflesia is an epiphytic plant which lacks chlorophyll. Thus it has to depend on the host for food and nutrition.

Thus the correct answer is (D) Rafflesia is an example of a parasitic epiphytic plant.

Additional Information: All parasitic plants have specialised root structures called haustoria which penetrate into the conducting tissues of the host plant and derive nutrition from them. For example Cucusta and Orobranche penetrate into the phloem of the host.

Note: Rafflesia is an obligate (not strict) epiphytic plant. It has a single large flower and lacks chlorophyll.