Cymose describes a type of flower cluster (inflorescence) where the main stem and each of its branches terminate in a flower. This means the oldest flowers are at the top or center, and new flowers develop lower down or to the sides.
Characteristics of a Cymose Inflorescence:
- Determinate Growth: The primary stem and branches end in a flower, halting further vertical growth.
- Oldest Flower Position: The oldest flower is located at the apex of the main stem or branch.
- Flower Development Pattern: Flowers bloom in succession from top to bottom or from the center outwards.
- Shape: Cymose inflorescences can be flat-topped or rounded, depending on the arrangement of the flowers.
Examples of Cymose Inflorescences:
While many plant families exhibit cymose inflorescences, some common examples include:
- Cherry blossoms (some varieties)
- Chickweed
- Campanula (Bellflower)
- Hydrangea (some species have both cymose and racemose structures)
Comparison to Racemose Inflorescences:
It's helpful to compare cymose to racemose inflorescences, which are the opposite:
| Feature | Cymose Inflorescence | Racemose Inflorescence |
|---|---|---|
| Growth Pattern | Determinate (ends in a flower) | Indeterminate (continues to grow) |
| Oldest Flower | At the apex (top or center) | At the base |
| Flower Blooming | Top to bottom or center outwards | Bottom to top |
| Common Example | Chickweed | Snapdragon |
Different Types of Cymes:
- Monochasium: A type of cyme with only one lateral branch at each node.
- Dichasium: A type of cyme with two lateral branches at each node.
- Polychasium: A type of cyme with multiple lateral branches at each node.
In summary, "cymose" refers to a specific arrangement of flowers where the oldest blooms are at the top/center, and the flowering pattern progresses outwards or downwards due to the determinate growth habit.
