# Usnea

Usnea is a type of lichen that grows on trees. It looks like a fuzzy green or gray beard hanging from branches. Lichens like Usnea are a sign of clean air in the forest.

- **Category:** [Fungi](https://www.snappit.app/explore/categories/fungi)
- **Rarity:** Common
- **Danger:** 1/5 · Very low
- **Snaps:** 1
- **Habitat:** Forests
- **Also known as:** Beard Lichen

![Usnea](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Usnea_australis.jpg&width=800)

Photo: CC BY-SA 3.0 · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Usnea_australis.jpg)

## Appearance

The Usnea has a stringy, bushy, or pendulous form, typically grayish-green. It visually differs from other hanging lichens by its distinctive, stretchy white elastic core, visible when gently pulled apart.

## Taxonomy

- **Kingdom:** Fungi
- **Phylum:** Ascomycetes
- **Class:** Lecanoromycetes
- **Order:** Lecanorales
- **Family:** Parmeliaceae
- **Genus:** Usnea

## Interesting facts

- Inside, Usnea has a unique, stretchy white core, like a tiny elastic band!
- It produces special acids to stop bacteria and fungi from growing!
- People have used Usnea for thousands of years in traditional medicines and dyes!
- Some Usnea live for hundreds of years, making them super ancient organisms!

## Special abilities

- **Air Filter Power:** Usnea can absorb pollutants from the air, helping scientists understand the health of our environment.
- **Sun Energy Creator:** Usnea has tiny partners inside that make their own food from sunlight, just like plants!
- **Weatherproof Protector:** Usnea can dry out completely and then rehydrate to continue growing, surviving harsh conditions.
- **Stretchy Support System:** Usnea has a strong, flexible inner core that helps it hang tough against wind and weather.

## Measurements & details

- **Height:** 5-50 cm
- **Edible:** inedible
- **Growth Substrate:** wood
- **Season:** Year-round

## Ecological connections

- **Symbiotic with:** Green Alga (*Trebouxia arboricola*) — provides food for the fungus
- **Eaten by:** [Caribou](https://www.snappit.app/explore/caribou) (*Rangifer tarandus*) — a vital winter food source
- **Eats:** [Black Slug](https://www.snappit.app/explore/black-slug) (*Arion ater*) — grazes on its surface
- **Shelter:** [Blue Jay](https://www.snappit.app/explore/blue-jay) (*Cyanocitta cristata*) — uses Usnea for nesting material

## Traits

- [Lichen](https://www.snappit.app/explore/traits/lichen): This trait describes a composite organism resulting from a symbiotic association between a fungus and a photosynthetic partner, typically an alga or cyanobacterium.
- [Evergreen](https://www.snappit.app/explore/traits/evergreen): Evergreen plants retain their foliage throughout the year, never shedding all their leaves at once.
- [Medicinal](https://www.snappit.app/explore/traits/medicinal): Medicinal plants possess chemical compounds that can be used for therapeutic purposes to treat illnesses or maintain health.
- [Ancient Lineage](https://www.snappit.app/explore/traits/ancient-lineage): This trait signifies organisms belonging to a very old evolutionary group with ancestors dating back millions of years.
- [Forest](https://www.snappit.app/explore/traits/forest): Forest habitats are terrestrial environments dominated by dense tree cover, supporting a high diversity of plant and animal life.

## Collections

- [Fungi](https://www.snappit.app/explore/collections/fungi)

## Safety

**Danger:** 1/5 · Very low

Usnea is safe to observe but avoid touching or picking it.

## Frequently Asked Questions

### How to identify Usnea?

Compare the cap shape, the underside, the stem and base, and whether the fungus grows on wood or soil. Some fungi have gills, others pores or teeth. A cap seen only from above often hides the most useful features. Mushroom Identifier: upload a photo and compare the visible details.

### How tall is Usnea?

5-50 cm

### Is Usnea edible?

inedible

### Where is Usnea usually found?

Forests

### What does Usnea grow on?

wood

### When is Usnea in season?

Year-round

## Where to spot

- [Bottle Creek Indian Mounds](https://www.snappit.app/guides/places/bottle-creek-indian-mounds) — Alabama, US · Historic Site

## More Fungi

- [Field Mushroom](https://www.snappit.app/explore/field-mushroom) (*Agaricus*)
- [Button Mushroom](https://www.snappit.app/explore/button-mushroom) (*Agaricus*)
- [Portobello Mushroom](https://www.snappit.app/explore/portobello-mushroom) (*Agaricus*)
- [Shiitake](https://www.snappit.app/explore/shiitake) (*Lentinula*)

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Source: [Usnea: Characteristics, Facts & Places to See — Snappit](https://www.snappit.app/explore/usnea)