Moss Impressive: 9 Facts About the Tiny and Mighty Plant

As Portland Japanese Garden takes part in Moss Appreciation Week, an annual celebration created with Lewis & Clark College, we wanted to share some of the most fascinating things we discovered about these small but remarkable plants. Moss may seem simple at first glance, but it has a rich history, important ecological role, and deep cultural significance in Japan and beyond. Let’s explore some amazing facts about moss.

1. Moss Has No True Roots

Unlike most plants, mosses and other bryophytes, including liverworts and hornworts, do not develop traditional roots. Instead, they grow structures called rhizoids. These tiny hair-like parts help anchor moss securely to surfaces such as soil, rocks, buildings, and other plants.

Although rhizoids do not function like normal roots that absorb nutrients and water, they are highly effective at helping moss remain attached wherever it grows.

2. Moss Is One of Earth’s Ancient Plants

Moss belongs to one of the oldest groups of plants on our planet. Scientists believe mosses evolved from ancient algae and were among the earliest plants to successfully move from aquatic environments onto land.

These small plants first appeared roughly 450 million years ago, making them survivors that have existed through countless changes in Earth’s history.

3. Some Gardens Are Home to More Than 100 Moss Species

Certain Japanese gardens contain an extraordinary variety of moss species, with some locations supporting more than 100 different types. One of the most commonly found species is Polytrichum commune, also called haircap moss.

Experts such as Yoshitaka Oishi, a leading moss researcher at Fukui Prefectural University, have pointed out that gardens can serve as important refuges for rare and endangered moss species, helping preserve biodiversity.

4. Moss Is Surprisingly Tough

Although moss prefers not to be walked on and does not tolerate long periods of intense sunlight, it is an incredibly durable plant. Some research has shown just how resilient these organisms can be.

According to moss researcher Ulrica Nordström, scientists were able to revive moss that had remained frozen in Antarctica for approximately 1,600 years. Moss has even endured experiments in space. In 2025, moss samples placed outside the International Space Station were returned to Earth, and many were still able to grow successfully.

5. Moss Can Reveal Environmental Changes

Moss is highly responsive to the conditions around it, which makes it useful for scientists studying environmental changes. Researchers use moss populations as indicators of climate-related impacts.

A decline in urban moss populations may signal problems such as urban heat islands, areas where concrete and asphalt absorb and retain heat, causing temperatures to rise. These warmer urban environments can affect both plant life and human health.

6. Moss Comes in Many Colors

Although people often imagine moss as simply green, there is no single color known as “moss green.” Moss species can display a wide range of shades depending on their environment and characteristics.

Along with different tones of green, moss can also appear in colors influenced by gray, red, yellow, and other subtle hues, creating beautiful variations in natural landscapes.

7. Moss Can Be Found Around the World

Mosses are extremely adaptable and can survive in many different regions across the globe. Some species have such broad distributions that they naturally appear in multiple continents.

Moss researcher Annie Martin has noted that studies of bryophytes in the Ozark region found that around 90% of the moss species there also occur throughout North America. Their ability to adjust to different environments is one reason moss can thrive in so many places.

8. Moss Has Been Used by People for Generations

Although moss is not commonly considered a food source today, some cultures have found practical uses for these plants. Indigenous communities have used species from the genus Racomitrium to prepare porridge.

Moss has also provided warmth and shelter. In northern regions, it has traditionally been used as an insulating material in homes because of its ability to help retain heat.

9. Moss Plays a Major Role in Storing Carbon

Rainforests are often described as the planet’s “lungs,” but mosses also perform an incredibly important environmental function. They are among the largest carbon storage systems found on land.

Peatlands dominated by Sphagnum moss can store more carbon than all rainforests combined. Protecting peatlands is therefore just as important as conserving forests, because losing these habitats can release large amounts of stored carbon into the atmosphere.

Moss may be small in size, but its history, resilience, ecological importance, and cultural value make it one of the most extraordinary plants on Earth.