Ferns — Polypodiaceae & Pteridaceae: Polypody & Brake Families
Ferns are not flowering plants. They lack the separate male and female structures that form the basis of most flowering plants’ reproductive processes. Instead of using seeds, ferns make spores. When spores fall on a suitably moist, shady place, they begin the fern’s reproductive cycle. Because ferns need liquid water for a crucial reproductive step, ferns are not found in sunny, dry locations. Fern structures have their own names:
- A fern’s leaf is called a frond. It is divided into pinnae, which may be subdivided into pinnules
- The underside of the pinnules contain sori, which in turn contain sporangia, which produce the spores
- Sori may be covered by a membrane-like indusium. A false indusium is a covering formed by a reflexed margin of the pinna / pinnule. Not all ferns have clearly defined sori
All ferns included here are native to California.