Tag: root - external morphology

Most orchids are epiphytes as they have epiphytic roots. Epiphytes are plants that grow anchored to other plants. They are non-parasitic. Epiphytic roots are adventitious roots found in the epiphytes. These roots are present in the air and absorb the moisture and nutrients from the air. Since epiphytic plants do not have roots in the soil, they are called as air plants. Epiphytic roots of orchids grow on the surface of other plants for getting shelter.

Groundnut, Bean and Alfalfa, all the three are legumes and thus the members of the family Leguminosae.

A haustoria is a root-like structure or a structure that grows into or around another structure to absorb water or nutrients. The root of a parasitic plant that penetrates the host's tissue and draws nutrients from it.

Symbiosis is a type of association of dissimilar organisms of their mutual advantage, e.g., association of nitrogen-fixing bacteria (nodule bacteria) with leguminous roots. The bacteria, inhabiting nodules on roots manufacture compounds from the nitrogen of the air, which becomes available to the plant. From the plant, bacteria obtain carbohydrates and other food materials.

Fungi are also known to form symbiotic relationship with plants (mycorrhiza). Many members of genus glomus forms mycorrhiza.

Bacteroid : Symbiotic bacteria Rhizobium leguminosarum in leguminous plants e.g., gram, pea etc. in their roots nodules produce Leg haemoglobin  this whole Bacteria + Leg haemoglobin + Polyploide  cells of roots is called as bacteroid. 

Nitrogen fixing bacteria are found in the root nodules of leguminous plants. Pea plant being a legume such bacteria would be found in its roots.