The Phrymaceae

The Phrymaceae also has a bilaterally symetrical corolla of 5 fused petals (like both the Lamiaceae and the Plantaginaceae), but it has stigma lobes that are flat and sensitive to touch.

Monkey flower with flat stigma lobes
Flower of Diplacus aurantiacus, showing flat stigma lobes.

These flat stigma lobes close when they are touched, presumably reducing the likelihood of self-pollination.

 This phenomenon was featured in one of your first lessons ("Plant Basics"). If you would like to see it again, visit the YouTube video at https://www.youtube.com/watch?v=O2RPIMoz7Mg.