Question

Stilt roots are reported from
(a) Pandanus (screw pine)
(b) Radish
(c) Mango-ginger
(d) Bryophyllum

Answer 1

Hint: Stilt roots are also seen in maize and sugarcane. They grow out from the lower nodes of the stem and are responsible for providing additional support to these plants as they are very tall and can fall down without proper anchorage.

Complete Answer:
Stilt root is a type of adventitious root as it did not arise from the roots or radicle. It is a type of aerial adventitious root that grows out from the basal nodes of the stem towards the ground where it gets firmly attached. Such roots are found in plants that are growing near river banks. It is seen in Pandanus (screwpine) as it is a pine tree, it is long and tall and thus requires some additional support.

Additional information: Let us look at the modifications in the other plants mentioned in the options.
Radish: The root found in radish (Raphanus sativus) is a modification of taproot. It is spindle-shaped and is modified to store food that is produced by the plant.
Mango-ginger: In plants like mango-ginger, the modification is seen in stem such that the stem grows underground horizontally and root and shoots grow out vertically from its nodes.
Bryophyllum: Bryophyllum has adventitious buds growing on its leaves which then fall down and grow into a new plant. It is a type of vegetative reproduction.
So, the correct option is ‘Pandanus (screw pine) ’.

Note:
- Taproot is a type of root found in dicots in which there is the elongation of the radicle to form a primary root which then branches into secondary, tertiary roots.
- Adventitious roots grow out from the branches of a banyan tree to support it and are known as prop roots.
- Some plants grow their roots vertically upwards known as pneumatophores when the soil has too much salinity or swamp causing suffocation of the roots.