• Asterids are the flowering plants that have best adapted themselves for pollination by insects. Their flowers are characterized by:
• They are all hermaphrodite. Having both male and female parts.
• They all have bilateral symmetry.
• Their stamens have a circular distribution.
• They show two fused carpels.
• Their petals tend to fuse, often forming tube-like shapes.
• The flowers are often organized in small tight bunches such as the case of lavender or mint.
• Composite flowers take this strategy to an extreme. Sunflowers for example are not a single big flower but a group of several hundreds of little flowers.
• Asterids, especially composite flowers, are the most successful type of flowers on earth, and due to this, the most common group.

Catnip; photo by Annie Roonie, cc-by