(1)

In monocotyledonous plants, the primary root is short-lived and is replaced by a large number of roots. These roots originate from the base of the stem and constitute the fibrous root system, e.g., wheat plant.

(2)

Sweet potato (Ipomoea batatas) is a swollen single root tuber that does not assume a definite shape. It is a modified adventitious root for storage of food.

(4)

Pistia (water lettuce) is a floating aquatic plant. In aquatic plants, roots are generally poorly developed and do not take part in absorption of water. Water is absorbed by the general body surface in these plants.