Dryopteridaceae

Wood ferns are a large group of plants. There are about 1700 kinds of them.

These ferns grow all over the world. Some grow in the dirt. Other kinds grow on trees.

Many people grow them in gardens. They look very pretty.

Some ferns have long stems. Other ferns can climb up things. They have many leaves.

These plants have been around a long time. They started a very long time ago.

It is fun to look for them in nature.

Wood ferns are a big group of plants. There are about 1700 species in this family. You can find them all over the world. Some grow in the dirt on the ground. Other kinds grow on trees. Many people grow them in gardens because they look nice.

These ferns have been around for a very long time. Fossil records show they appeared about 99 million years ago. This was during the Mid Cretaceous period.

Wood ferns have many different parts. They have rhizomes, which are thick stems that grow along the ground. Some of these stems can even climb. Their leaves are called fronds. Most fronds look the same, but some can be scaly.

On the back of the leaves, you might see sori. Sori are small round spots. These spots hold the spores. Spores are tiny bits that help the plant make new plants. Some sori are covered by a thin part called an indusium. This part acts like a tiny lid or shield. The largest groups of these ferns include Elaphoglossum and Polystichum.

Wood ferns belong to a large family called Dryopteridaceae. This group is made of many different kinds of ferns. Scientists say there are about 1700 species in this family. You can find these plants all over the world. Some grow in the dirt on the ground. Other kinds grow on trees or rocks. Many people grow them in gardens to look pretty.

These ferns have a special way they grow. They have rhizomes, which are thick stems. These stems can grow along the ground or stand up straight. Some rhizomes even climb up things. The leaves of the fern are called fronds. Most fronds look the same on one plant. On the bottom of the leaves, you may see sori. Sori are small round spots that hold spores. Some sori have an indusium, which is a tiny shield.

These plants have been around for a very long time. The fossil record shows they began to appear a long time ago. This happened about 99 million years ago. That time was during the Mid Cretaceous period. They split from other plant families about 100 million years ago. It is amazing to think they have lived through so much history.

Scientists have worked hard to name these plants. In 1990, Karl U. Kramer defined the family in a broad way. Later, in 2006, Smith and others changed the groups. They used DNA studies to find the right connections. Some groups, like Elaphoglossum, are very large with over 600 species. Polystichum is another big group with 260 species. Dryopteris has 225 species, and Ctenitis has 150 species.

Learning about these ferns helps us see how nature works. We can see how plants use tiny spores to make new life. We can also see how they find places to live. Some find a home in the soil. Others find a home high up on a tree. This shows how life can find a way in many spots. Studying them helps us understand the history of our Earth.

The Dryopteridaceae are a diverse family of leptosporangiate ferns. They are commonly known as wood ferns. This group is part of the order Polypodiales. Scientists classify them within the suborder Polypodiineae. This classification comes from the Pteridophyte Phylogeny Group (PPG I) in 2016. There are about 1,700 different species in this family. These plants are found all over the world. They are known for their cosmopolitan distribution. Many species are grown by people as ornamental plants.

These ferns have very specific physical structures. They grow from rhizomes, which are thick underground or surface stems. These rhizomes can be stout, creeping, or even climbing. They often have nonclathrate scales at their tips. The leaves of the fern are called fronds. Most plants have monomorphic fronds, meaning they look mostly the same. Some plants have dimorphic fronds, which means they have two different types. The stalks of the leaves are called petioles. Inside these petioles, vascular bundles carry water and nutrients. These bundles are often arranged in a ring. The veins in the fronds can be free or they can join together. This joining process is called anastomosing.

Reproduction in wood ferns happens through specialized structures. On the underside of the leaves, you may find sori. Sori are clusters of sporangia, which are tiny cases that hold spores. Some lineages have acrostichoid sori. This means the sori cover the entire underside of the leaf. Many sori have an indusium. An indusium is a thin, protective covering. It can be round, kidney-shaped, or peltate, which means shield-like. The sporangia themselves have stalks that can be short or long. The spores they release are often reniform, meaning they are kidney-shaped. They can also be winged or monolete.

Wood ferns have lived on Earth for a very long time. The fossil record shows they emerged during the Mid Cretaceous period. This was approximately 99 million years ago. They diverged from other families in the eupolypods I group about 100 million years ago. This long history shows how successful the family has been.

The family is divided into several large groups called genera. Four genera make up about 70% of all species in the family. The largest is Elaphoglossum, which has over 600 species. Polystichum is the second largest with 260 species. Dryopteris follows with 225 species. Ctenitis is the fourth largest with 150 species.

Taxonomy, or the science of naming organisms, has changed for this family. In 1990, Karl U. Kramer defined the family very broadly. He included several other groups like Woodsiaceae and Onocleaceae. However, later DNA studies showed this version was polyphyletic. This means the group did not all come from one single ancestor. In 2006, Smith and other scientists split the family up. Modern studies use DNA sequences to find true relationships. For example, a 2007 study showed Pleocnemia should move to Dryopteridaceae. In 2012, scientists also moved several genera into the Dryopteris group.

The PPG I classification organizes the family into three subfamilies. The first is Polybotryoideae. This includes genera like Polybotrya and Maxonia. The second is Elaphoglossoideae. This group contains the very large Elaphoglossum genus. It also includes genera like Bolbitis and Mickelia. The third subfamily is Dryopteridoideae. This includes the common Dryopteris and Polystichum genera.

Understanding these ferns helps us learn about plant evolution. Scientists study how they grow in different environments. Some are terrestrial, meaning they grow in soil. Others are epiphytic, meaning they grow on other plants. Some are epipetric, which means they grow on rocks. Others are hemiepiphytic. By studying these patterns, we see how life adapts to many different places.