cymes

A cyme is a type of inflorescence in flowering plants characterized by determinate growth, in which the terminal flower forms first at the apex of the main axis. Once this flower develops, further flowers arise from lateral buds below the apex, giving the overall inflorescence a distinct, often compact appearance. This contrasts with indeterminate inflorescences like racemes, where the main axis continues to elongate and new flowers form below the growing tip.

Cymes are commonly classified into monochasial and dichasial forms. Monochasial cymes produce a single series of flowers along one side of the axis. This subgroup includes helicoid cymes, in which successive flowers arise on the same side to create a curved, spiral-like arrangement, and scorpioid cymes, which form a zigzag or coiled pattern reminiscent of a scorpion’s tail. Dichasial cymes produce two opposite lateral branches or flowers at each developmental stage, giving a more two-sided, branched appearance.

The cyme is widespread across many angiosperm groups and is especially prominent in various dicot lineages. The arrangement of flowers in cymes can influence pollination dynamics by presenting flowers in a compact, terminal cluster and shaping the accessible floral display for pollinators. The term derives from Greek kyma, broadly associated with a swelling or projection, reflecting the clustered, terminal nature of many cymes.

See also: inflorescence, raceme, panicle, umbel.