The reproductive organs of flowering plants are the flowers. Flowers are produced after a period of vegetative growth. The flowers may be borne singly or in clusters.
Flowers when borne singly are said to be solitary (eg) Hibiscus rosa sinensis (shoe flower), if in clusters they form an inflorescence. Inflorescence When several flowers arise in a cluster on a common axis, the structure is referred to as an inflorescence.
The common axis is the inflorescence axis which is also called as rachis or peduncle. Several single flowers are attached to the inflorescence axis. In case of plants possessing underground rhizomes, the rachis or peduncle arises directly from the rhizome. Such a rachis is referred to as scape. In the case of lotus, the scape gives rise to a solitary flower.
In plants like onion, the scape gives rise to an inflorescence. Based on the location, the inflorescence may be classified into 3 types.
(i) Terminal Inflorescence
(ii) Intercalary Inflorescence and
(iii) Axillary Inflorescence.
In plants like Callistemon the inflorescence is found in between the stem. This is called intercalary inflorescence. Generally, based on the arrangement, structure and organisation of flowers on the axis, inflorescences are classified into various types.
There are four major types. i) Racemose
iii) Mixed and
iv) Special types