Question

Definition of parasitic plants.

Answer 1

Hint: Parasitic plants are those that feed on other organisms called hosts. Parasitism is a major threat to the host species of parasites as they cause damage to them. The hosts suffer dangerously. But the parasites get benefitted from their hosts in several ways.

Complete step by step answer: Parasite term has arrived from the Greek word ‘parasitos’ that means eating on another's table. Thus parasites are those organisms that feed on the nutritional contents of other organisms. This is a type of symbiotic relationship. But here only the parasite gets benefitted. The host is the organism on which the parasite feed suffers deficiencies.
-The parasitic plants are those plant species that stick around other plants and sucks their food to meet their requirements. About 4,500 species of parasitic plants are known. They comprise one percent of Angiosperms.
-The parasitic plants detect their hosts by identifying some chemical compounds released by their host plants or soil in which they stand. All the parasitic species are characterized differently based on their site of feeding over the host plant and the way they get their food.
-The nutrition derived by parasitic plants is derived from the conducting tissues of the host plants. Some parasitic plant species derive their nutrition by sucking the contents of xylem and are termed as xylem-feeding.
-On the other hand, some of the parasitic plants prefer feeding on the phloem tissue of the host and thus they are called phloem feeding. The sucking is performed by haustorium. These are root-like structures that swirl around the host stem and penetrate its conductive system.
-These plants can be classified as obligate parasites and facultative parasites. The former cannot survive without the host and the latter can survive independent of the host.

Note: Parasitic plants feed on healthy plants. This can lead to crop destruction. Thus, they are of major economic importance. Cuscuta is a phloem-feeding parasitic plant that attacks crops like potatoes, clover, etc.