Question

Which of the following sclereids are the characteristic of intercellular spaces of Nymphaea?
A. Osteosclereids
B. Brachysclereids
C. Macrosclereids
D. Astrosclereids

Answer 1

Hint: Nymphaea or water lily is a large group of aquatic rhizomatous perennial herbs. The leaves of these herbs have strengthening sclereids. Sclereids are a reduced form of sclerenchyma cells. These can occur singly or in groups with thickened lignified cell walls.

Complete answer:
The sclereids constitute the small bundles of layers of tissue that are durable and provide strength to the regions where they are found. These are reduced forms of sclerenchyma cells of the plant. Sclereids can have varying shapes like prosenchymaic, forked, isodiametric, or elaborately branched. The sclereids are usually found in the vascular tissues, epidermis, or ground tissue of plants.
The elaborately branched sclereids are highly reduced forms of sclerenchyma. These are relatively short sclerenchyma cells. The branches of this sclereid type are clearly visible. These sclereids may be present singly or in small groups. This type of sclereids is called astrosclereids. They are present in the mesophyll of leaves of aquatic perennial herbs like Nymphaea. The Astrosclereids provide strength to the leaves and thus they act as strengthening agents.
Nymphaea is commonly known as water lilies. They have an angular and erect stem with eaves growing from the rhizome. They have long petioles. The water lilies float with their round leaves growing up to the diameter of 12 inches. They have disc-shaped leaves that are split to the stem in a V-shaped manner at the center. The leaves are often purple underneath. The strength of leaves comes majorly from astrosclereids.
Hence, option D is the correct answer.

Note: The flowers of Nymphaea grow out of the water or they float on the surface of the water. The flowers open either during the day or night. Water lilies show protogynous flowering. The first flower opens with female pistils and then closes. When the flower reopens it displays male stamens. flowers are pollinated by insects or bees.