Tag: growth and development in plants

Perianth is represented by membranous scales called as lodicules, they may be 2 or 3 and also interpreted as relictual perianth.

Glumes represent bracts. Glumes are a basal, membranous, outer sterile husk or bract in the flowers of grasses (Poaceae) and sedges (Cyperaceae). A bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger or of a different colour, shape or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals. 
Thus, the correct answer is option A.

Autogamy is pollination within a flower. Chasmogamous flowers are those in which anthers and stigma are exposed. For autogamy, in such a flower to take place, pollen and ovule should mature simultaneously and anther and stigma should lie close to each other.

The non-essential parts of the flower are those that are not involved in the process of fertilization directly. These are called the accessory whorls. The calyx (made up of sepals) and corolla (made up of petals) represent the accessory whorls. In some flowers, the calyx and corolla are not differentiated or distinct. Then the resultant structure is called perianth whose individual units are called tepals.

The flowers of Bougainvillea are bright pink in colour because of the colour of the bracts. These flowers do not have a distinct and differentiated corolla as well as calyx. Three tiny flowers are surrounded by the bracts. These bracts are modified leaves. They protect the flower and attract the pollinators.

When the flowers are laterally borne, then the side of the flower towards the apex of central axis or mother axis is considered to be the posterior side in a floral diagram while the side opposite to the posterior side is towards bracts and is called the anterior side. So, side of the flower towards the bract is called the anterior side.

In some flowers like onion and Asphodelus, the calyx and corolla are not distinct. They are collectively called the perianth. The perianth is an accessory whorl whose individual member is called tepal. Based on the appearance, the tepals can be petaloid (coloured) or sepaloid (green).

When the calyx and corolla are indistinct and undifferentiated, the resultant whorl is called the perianth. 

The term perianth is used to refer to the condition when the calyx and corolla are not differentiated. In grasses, the similar condition is seen by the presence of lodicules, that are situated below the ovary. 

The whorl perianth represents undifferentiated calyx and corolla. Its individual units are called tepals. Tepals can be petaloid if coloured bright or sepaloid if green.