Families with 5 fused petals and superior ovaries

This lesson will cover how to distinguish seven families of common plants that have five fused petals and superior ovaries.

This lesson does not cover ALL families with 5 fused petals and superior ovaries. You will encounter at least one more in future lessons.

The families we will cover here are:

• the Boraginaceae
• the Hydrophyllaceae
• the Malvaceae
• the Solanaceae
• the Lamiaceae
• the Phrymaceae
• the Plantaginaceae

The first four have radially symmetrical flowers. Among those:

Plants in the Boraginaceae and Hydrophyllaceae bear their flowers in coiled cymes. The primary difference between them is that members of the Boraginaceae have deeply lobed ovaries and fruit segments disperse as single-seeded nutlets, whereas members of the Hydrophyllaceae have unlobed or shallowly lobed ovaries that become capsules.

Plants in the Malvaceae have their filaments fused into a tube around the style.

Plants in the Solanaceae have somewhat varied flower shapes, but they don't have coiled cymes or filaments fused into a tube around the style.

The last three have bilaterally symetrical flowers. Among those:

Plants in the Lamiaceae have deeply lobed ovaries. Those lobes disperse separately at maturity as single-seeded nutlets.

Plants in the Phrymaceae have unlobed ovaries that become capsules and stigma lobes that are flat and close when touched.

Plants in the Plantaginaceae have unlobed ovaries that become capsules (like the Phrymaceae), but they do not have the touch-sensitive stigma lobes.