Question

Hydrophily is best demonstrated by?
A. Nelumbium
B. Vallisneria
C. Nymphaea
D. Ranunculus

Answer 1

Hydrophily refers to pollination by means of water. In Vallisneria, the plants show hydrophily as the male flower gets detached from the plant and it floats on the water and comes in contact with the stigma of the female flower.

Complete answer:
OptionA- Nelumbo, which is a genus of aquatic plants. It has large and showy flowers. Members are commonly called lotus. Though "lotus" name is also applied to various other plants and plant groups, including the unrelated genus Lotus.

Option B, is Vallisneria. It is a genus of freshwater aquatic plants. These are known as eelgrass, tape grass or vallis. The flowers of this genus are widely distributed in tropical and subtropical regions of Asia, Africa, Europe, and North America. Vallisneria is a submerged plant. It spreads by runners and sometimes forms tall underwater meadows.

Option C Nymphaea, it is a genus of hardy and tender aquatic plants in the family Nymphaeaceae. The genus shows cosmopolitan distribution. Many species of this genus are cultivated as ornamental plants, whereas many cultivars have been bred. Some occur as introduced species where they are not native, and some are weeds.

Option D Ranunculus, it is a large genus of flowers. It consists of about 500 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups. They are also known as spearworts and water crowfoots.

So the correct option is 'Vallisneria'.

Note:
Hydrophily is a fairly uncommon form of pollination. In this, the pollen is distributed by the flow of waters, particularly in rivers and streams. Hydrophilous species are of two categories: plants that distribute their pollen to the surface of water, eg- Vallisneria's male flower and plants that distribute it beneath the surface. e.g. seagrasses.