Botany and Plant Science

Hypohydrogamy includes the plants which are pollinated inside the water, e.g., Ceratophyllum, Naja, etc. Epihydrogamous - includes the plants which are pollinated on the surface of water.

• Hydrophily is the pollination by means of water. In Vallisneria, the male flower is detached from the plant and float on the surface of the water and is bought in the contact of the stigma of the female flower. 

Pollination mechanism in Salvia is a unique lever type. The flowers in this genus are arranged in thyrsus inflorescence and they are attractive and well adapted for cross-pollination through the agency of insects. In this lever mechanism of pollination, the Corolla has a spreading upper lip, which acts as a landing place for the insect. When the insects land on the lower lip of the corolla and in its endeavour to obtain nectar that is secreted by the hypogynous disc, pushes the sterile lobes of the stamen inwards. Due to this the upper half of the connective with the fertile lobes act as a lever. Then the anther lobe comes down and shed the pollen on the back of the insect.

Lever mechanism for pollination is characteristic feature of Salvia. The flowers in this genus are arranged in thysrus inflorescence and they are attractive and well adapted for cross pollination through the agency of insects. In this mechanism of pollination, the corolla has a spreading upper lip, which acts as a landing place for the insect. When the insects land on the lower lip of the corolla and in its endeavour to obtain nectar that is secreted by the hypogynous disc, pushes the sterile lobes of the stamen inwards. Due to this the upper half of the connective with the fertile lobes act as a lever. Then the anther lobe comes down and shed the pollen on the back of the insect.

Pollination by means of water is called as Hydrophily. In Vallisneria, the male flower is detached from the plant and it will float on the water and are bought in the contact of the stigma of the female flower.

All the flowers are important to plant as they attract pollinators by producing nectar, attracting pollinators and helps to plants in the reproduction process by pollination.

In Vallisneria, pollination is hydrophilous. Pollination carried out through water is hydrophily. Light and unwettable pollen grains are present in these plants. Pollen grains are surrounded by mucilaginous covering, hence protected from wetting.

Pollination in Vallisneria is epihydriphilous. It is a type of hydrophily which occurs on the surface of water. The female flower have a very long pedicel, therefore it reaches the surface of water. Male flowers after breakage floats on the surface of water. Pollen grains are released on to the surface of water. They are carried passively by water currents, some of them eventually reach the female flowers and the stigma.

The process of transfer of pollen grains from the anther to stigmatic surface of the flower with the help of water is hydrophily. Pollination by water is quite rare in flowering plants and is limited to about 30 genera, mostly monocots, e.g. freshwater plants like Vallisneria, Hydrilla; marine water plants like Zostera. Light unwettable pollen grains are present in these plants. Pollen grains are surrounded by mucilaginous covering, hence protected from wetting. Stigma is long, sticky and unwettable.

Both wind and water pollinated flowers typically lack bright colors, nectar, and scent, as they do not need to attract animal pollinators. They rely on the physical movement of the medium to transport pollen.

In hydrophily (pollination by water), pollen grains are often protected by a mucilaginous covering to prevent wetting and have a specific gravity that allows them to float or remain submerged at the level of the stigma.

Sclerenchyma cells are characterized by relatively thick, lignified secondary cell walls. The lignified wall gives sclerenchyma cells their rigidity, and they function primarily in mechanical support and water conduction. They also make up most rigid parts of the plant (e.g., seed coats and some fruit walls) and are often positioned so that they provide mechanical protection for softer plant parts. 

Sclerenchyma is the supporting tissue in plants. Two types of sclerenchyma cells exist: fibers and sclereids. Their cell walls consist of cellulose, hemicellulose and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation where as Stomata are cell structures in the epidermis of tree leaves and needles that are involved in the exchange of carbon dioxide and water between plants and the atmosphere.