Understanding Cymose Inflorescence: The "Top" Flowering Types

What Is a "Top" Inflorescence?

In botany, a "top" (cyme) is a determinate inflorescence where the terminal flower blooms first, halting main-axis growth. Lateral buds then develop into flowers, each ending growth. This creates a structured, often symmetrical flowering pattern.

Classification by Branching

• Monochasial (uniparous): One lateral branch per node. Helicoid (cincinnius) coils alternately; scorpioid (circinate) curls like a scorpion's tail (typical of Boraginaceae: forget-me-not, borage, heliotrope).
• Dichasial (biparous): Two opposite branches per node. Forms a false panicle over levels. Common in Caryophyllaceae and Gentianaceae.
• Polychasial (multiparous): More than two branches per node.

Simple vs. Composite

Simple: main axis bears flowers directly. Composite: main axis bears secondary inflorescences.

Key Examples

Hemerocallis (daylily) shows helicoid cyme. Iris germanica exhibits rhipidium—a flat, one-plane helicoid. These patterns help identify plant families and understand reproductive strategies.