What’s this on the back of my holly ferns?

Thanks to Heidi Schaub for this great question and picture! What are these growths on the undersides of her Japanese holly ferns?

These are spores, which indicate a very happy plant. Ferns are ancient plants that reproduce from spores, rather than going to all the trouble of producing flowers to attract unreliable pollinators.

Ferns are native to areas with high relative humidity, which is important in their reproductive cycle.

Here in Central Texas, we have a beautiful little native fern, which can easily be seen while hiking along our many creeks and green belts, southern maidenhair fern, (Adiantum capillus-veneris).

When the spores are ripe, they will dry up and fall off. In the right conditions, they will create new plants.