Question

Among the following, which plant is completely devoid of roots?
A. Ceratophyllum
B. Hydrilla
C. Vallisneria
D. Azolla

Answer 1

Hint: The referred plant is a cosmopolitan genus of flowering plants that is, it is usually present everywhere. It is commonly found in ponds, marshes, and quiet streams. It is present in tropical and in temperate regions.

Complete answer:
Ceratophyllum is the genus of an aquatic flowering plant. It is a cosmopolitan plant that can be found near ponds and marshes in tropical and temperate climatic areas. The flowers of this plant are small. This is a submerged plant, which means a portion of it is present underwater. They may be branched with a single branch per node. Lacks roots, but sometimes leaves are modified to perform the function of the roots. It belongs to the family Ceratophyllaceae and orders Ceratophyllales.
Moreover, a species of Ceratophyllum, referred to as hornworts because of their spiny fruits are submerged aquatic plants that are mostly free-floating and occur in freshwater lakes and ponds and in slow-moving water.

Thus, the correct answer is option ‘A’ – Ceratophyllum.

Additional information:
Hydrilla is a genus of aquatic plant, where the stems grow up to 1-2m long, and the leaves are arranged in whorls of two to eight around the stem. Vallisneria is a submerged plant that spreads by runners and sometimes forms tall underwater meadows. Azolla is considered an invasive plant in wetlands, freshwater lakes.

Note: Ceratophyllum lacks true roots and has dissected, whorled leaves with too thick margins. Flowers of Ceratophyllum have narrow and inconspicuous sepals or petals. The flowers are usually very small.