Cymose Inflorescence

Different types of the cymose inflorescence are studied in this experiment

The details of this experiment are as follows:

Locally available plants of Hibiscus, Hamelia, Heliotropium, Jasmine, Dianthus and Calotropis are collected for the study.

Based on the observed morphological characters, the inflorescence type is identified and the position of the ovary with respect to other floral whorls is also documented.

Introduction to the experiment: Inflorescence is the mode of development and arrangement of flowers on a stem or lateral branches. The cymose inflorescence is characterised by the presence of a flower at the apex of the inflorescence axis (peduncle) and flowers arranged in a basipetal sequence. Based on growth and development, cymose inflorescence is classified into many types.

The types of cymose inflorescence discussed in this experiment are as follows:

Solitary cyme: This type of inflorescence is present in the Hibiscus plant and consists of a single flower arranged at the tip of the inflorescence axis.
Monochasial cyme: Also known as uniparous cyme, it is a type of inflorescence in which the main axis is terminated and produces one lateral branch. Based on the branching pattern, it is of two types
- Scorpioid: This type of inflorescence is present in the Heliotropium plant in which the lateral branches terminate in a single flower and arise from both sides of the peduncle, forming a zig-zag structure.
- Helicoid: This type of inflorescence is present in the Hamelia plant in which the lateral branches terminate in a single flower and always arise on the same side, forming a helical structure.
Dichasial Cymose: Also known as biparous cyme, in this type of inflorescence, the peduncle terminates in the flower and gives rise to two lateral branches; these lateral branches also terminate in the flower. The Dianthus plant exhibits this inflorescence type.
Polychasial Cymose: Also known as multiparous cyme, in this type of inflorescence, the peduncle bears a single terminal flower and gives rise to more than two lateral branches, each lateral branch with a single terminal flower. The Calotropis plant exhibits this inflorescence type.

The hypogynous ovary is observed in the flowers of Hibiscus, Heliotropium, Jasmine, Dianthus and Calotropis plants whereas the Epigynous ovary is in Hamelia.

FAQs on Cymose Inflorescence

Q1: Define inflorescence.

Ans: The inflorescence is the mode of development and arrangement of flowers on a stem or lateral branches.

Q2: Define cymose inflorescence.

Ans: The cymose inflorescence is characterised by the presence of a flower at the apical part of the peduncle or inflorescence axis. Flowers are arranged in basipetal succession, i.e. older flowers are at the apex, and younger flowers are at the base of the peduncle.

Q3: What are the advantages of flowers in inflorescence?

Ans: Inflorescences are complex structures that facilitate reproduction by presenting flowers in space and time and facilitate fruit development and seed dispersal. Inflorescence in reward-producing plants can facilitate pollination by attracting pollinators.

Q4: Mention the characteristics of the peduncle in cymose inflorescence.

Ans: The growth of the peduncle is terminated by the development of flowers in the apical tip. Immature flower buds are present at the bottom of the peduncle, and the older flower buds are towards the apex of the peduncle.

Q5: List the types of cymose of inflorescences.

Ans: The types of cymose inflorescences are as follows:

– Monochasial cymose is further classified into Helicoid cyme and Scorpioid cyme.
– Dichasial cymose
– Polychasial cymose
– Cyathium, verticillaster, and hypanthium are also modified types of cymose inflorescences.