Cymose Inflorescence and Its Types - Practice Questions & MCQ

Cymose Inflorescence and Its Types 

Cymose Inflorescence:

• This type of inflorescence is also known as determinate or definite inflorescence.
• Each peduncle or axis, whether main or axillary terminates into a flower.
• Younger flowers arise from the base of the older ones.
• Hence, the arrangement of flowers is in basipetal succession, that is, the older ones appear at the top and the younger ones at the base.

1. Solitary Cymose:

• It is the most simple type of inflorescence.
• The main axis does not branch and always ends in a single flower.
• For example, China Rose, Hibiscus, etc.

2. Uniparous / Monochasial Cyme:

• Main axis terminates into a flower.
• The lateral branch arise at the base of the terminal flower and acts as main axis.
• It also terminates into the flower.
• Monochasial cyme is of two types:

1. Helicoid Monochasial Cyme: successive branching occurs at the same side such that the inflorescence acquires helical shape, e.g., Begonia, Drocera, etc.
2. Scorpioid Monochasial Cyme: successive branching occurs on both sides in zig-zag or alternate manner, e.g., Ranunculus.

3. Dichasial / Biparous Cyme:

• The main axis terminates into a flower.
• Two new lateral branches arise from the base of the older one.
• These also end in flowers.
• The older flower appears in the centre while the younger flowers are towards the periphery. This type of arrangement in called centrifugal succession.
• For example, Bougainvillea, Dianthus

3. Polychasial / Multiparous Cyme:

• The main axis terminates into a flower.
• Many new flowers arise at the base of the older flower.
• For example, calotropis

4. Cymose Head:

• The peduncle is flattened.
• Many sessile and centrifugally arranged flowers are seen around the peduncle.
• The difference between racemose head and the cymose head inflorescence is of the arrangement of florets.
• The arrangement is centripetal in the racemose head while it is centrifugal in the cymose head.
• For example, Acacia