Question

Define Parasitic roots , reproductive

roots and prop roots

Answer 1

Parasitic or Haustorial roots : Plants which depend on plant partially or totally for their food material are known as parasites. The roots of parasitic plants, which penetrate into the host tissues to absorb nourishment, are called haustorial roots. The haustorial roots of Cuscuta (Dodder, vern. Amarbel) penetrates the host upto phloem and xylem to absorb organic food, water and minerals. The haustorial roots of partial parasite – Viscum (Mistletoe) penetrate upto xylem of host to absorb water and minerals.

- Parasite which absorb their nutrients from the host stem are known as stem parasites while those which absorb their nutrients from the host root are know as root parasite.
Reproductive roots : Some fleshy adventitious root develop buds which can grow in to new plants. These are called reproductive root. These roots serve as means of vegetative propagation. e.g., Sweet potato, Dahlia etc.
Prop Roots:

These adventitious aerial roots arise from horizontal aerial branches of the trees like Ficus bengalensis (Banyan).
Initially, they are hygroscopic in function, become red in moist condition and possess root-caps at their apices.

They grow vertically downward, penetrate the soil, become thick and assume the shapes of pillars.

They provide support to the spreading branches of tree.

Sometimes the main trunk dies and it is replaced by prop roots which assume the shapes of trunks.

In India, the biggest banyan tree having large number of prop roots is found at Indian Botanical Gardens, Kolkata and Kadiri (Andhra Pradesh).