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:
- Helicoid Monochasial Cyme: successive branching occurs at the same side such that the inflorescence acquires helical shape, e.g., Begonia, Drocera, etc.
- 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