Marattiaceae

Some ferns are very special.

These plants have very big leaves. Some leaves can grow very long. One kind grows in places like Java. Its leaves can be 9 meters long!

These ferns have thick roots. Some people can even eat these roots. They call one kind the potato fern.

One fern has tiny holes on its leaves. These holes are the largest in the plant world.

These ferns have been around for a long time. They lived on Earth a long time ago. It is fun to learn about them!

Marattiaceae is a family of ferns. These ferns are very old. Their history began over 300 million years ago. This was during the Carboniferous period.

Many of these ferns look different from common plants. They often have thick, fleshy rootstocks. Some ferns in this group have very large fronds. Fronds are the leaves of a fern. The genus Angiopteris has huge leaves. In Java, one species grows 9 meters long.

Some ferns are also useful for food. The potato fern is a large plant. It has a fleshy rhizome, which is a type of root. Some people use this part for food.

There are many different kinds of these ferns. Scientists group them into six genera. One kind is named Christensenia. These plants are small. But they have very special parts. They have the largest stomata in the plant world. Stomata are tiny holes on a leaf. These holes help the plant breathe. There are about 110 to 111 species in this family.

Marattiaceae is a unique family of living ferns. These plants are part of a special group called Marattiales. They are quite different from the ferns most people see every day. Many of these ferns have huge, fleshy rootstocks. Some even grow the largest leaves of any known fern. These leaves are called fronds.

These ferns work in a special way to make spores. Most ferns are leptosporangiate ferns. This means they start from a single cell. Marattiaceae are eusporangiate ferns. This means their spore cases form from a group of cells. The genus Angiopteris is very special too. It uses explosive ways to spread its spores. This helps the plant move to new places.

Scientists have spent a long time studying these plants. In 2006, a group named Smith et al. used molecules to study them. They thought the family belonged to its own class. Later, in 2009, Mark W. Chase and James L. Reveal changed this. They moved the group to a subclass called Marattiidae. The Pteridophyte Phylogeny Group in 2016 kept this new rank.

There are about 110 or 111 species in this family. They belong to six different genera. One genus is Angiopteris, which lives in places like Java and Madagascar. In Java, one species has fronds 9 meters long. Another genus is Christensenia, named for Carl Christensen. These plants are small but have very large stomata. Stomata are tiny holes that help plants breathe.

You might find these ferns useful or interesting in nature. The Ptisana salicina is called the potato fern. Some indigenous peoples use its fleshy rhizome for food. The genus Danaea lives in the Neotropics. It has leaves that look different from the others. These ferns have a very long history. Their ancestors lived over 300 million years ago. This was during the Carboniferous period.

Marattiaceae is a unique family of living ferns. It is the only living family within the order Marattiales. This order is the sole member of the subclass Marattiidae. These plants are quite different from common ferns found in temperate zones. They often possess massive, fleshy rootstocks. Some members also grow the largest fronds of any known fern.

These ferns use a specific biological mechanism to create spores. Most ferns are classified as leptosporangiate ferns. In those plants, the sporangium forms from a single initial cell. Marattiaceae are known as eusporangiate ferns. This means their sporangia develop from a group of many cells. Two genera, Angiopteris and Marattia, are even more unusual. They undergo monoplastidic meiosis. This is a rare process among euphyllophytes.

The family is divided into six distinct genera. The genus Angiopteris is found in Australasia, Madagascar, and Oceania. Its fronds are famously large. The species Angiopteris teysmanniana in Java can reach 9 meters in length. Another genus, Marattia, exists in the neotropics and Hawaii. The genus Eupodium is also neotropical and has three species. It was named for its distinctive stalked synangia. Synangia are structures where spore cases are fused together.

Other genera show even more specialized traits. The genus Ptisana is a paleotropical group. It includes the "king fern," Ptisana salicina, found in New Zealand. This plant is sometimes called the potato fern. Some indigenous peoples use its edible fleshy rhizome as food. The genus Christensenia is named after the Danish pteridologist Carl Christensen. These plants are relatively small. However, they possess the largest stomata in the plant kingdom. Stomata are the tiny pores plants use to breathe.

Classification of these ferns has changed as science progressed. In 2006, Smith et al. used molecular phylogeny to study them. They originally placed Marattiales in the class Marattiopsida. In 2009, Mark W. Chase and James L. Reveal lowered this rank. They moved the group to the subclass Marattiidae. The Pteridophyte Phylogeny Group (PPG I) maintained this rank in 2016. This system recognizes about 111 species within the family.

The evolutionary history of Marattiaceae is incredibly long. They are one of the earliest branching lineages of ferns. The earliest members appeared during the Carboniferous period. This was over 300 million years ago. The group has an extensive fossil record. This record stretches from the Carboniferous into the Jurassic period. However, fossil records after the Jurassic are quite scarce. Many extinct taxa once belonged to this lineage, such as Psaronius and Asterotheca.

Understanding Marattiaceae helps scientists study plant evolution. The genus Angiopteris is unique for its spore dispersal. It uses an explosive method to spread its spores. This trait may help the plant spread to new areas. In some locations, Angiopteris evecta has become an invasive species. It has naturalized in Hawaii, Costa Rica, and Jamaica. These plants escaped from botanical gardens. They show how even ancient lineages can impact modern ecosystems.