North America Native Plant

Forest Alsophila

Botanical name: Alsophila amintae

USDA symbol: ALAM5

Life cycle: perennial

Habit: shrub

Native status: Native to Puerto Rico  

Synonyms: Alsophila dryopteroides (Maxon) R. Tryon (ALDR3)  âš˜  Cyathea dryopteroides Maxon (CYDR2)   

Forest Alsophila: A Critically Endangered Puerto Rican Tree Fern Worth Protecting Meet the forest alsophila (Alsophila amintae), one of Puerto Rico’s most endangered botanical treasures. This remarkable tree fern represents both the incredible diversity of the island’s native flora and the urgent need for plant conservation efforts in tropical ecosystems. ...

Rare plant alert!

Region: United States

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Status: Endangered: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Forest Alsophila: A Critically Endangered Puerto Rican Tree Fern Worth Protecting

Meet the forest alsophila (Alsophila amintae), one of Puerto Rico’s most endangered botanical treasures. This remarkable tree fern represents both the incredible diversity of the island’s native flora and the urgent need for plant conservation efforts in tropical ecosystems.

What Makes Forest Alsophila Special?

Forest alsophila belongs to the ancient lineage of tree ferns, plants that have graced our planet for millions of years. Unlike the typical ferns you might find in your garden, this species develops a woody, multi-stemmed structure that can reach impressive heights of up to 13-16 feet under ideal conditions, giving it an almost prehistoric appearance that’s both striking and mysterious.

You might also encounter this species under its scientific synonyms, including Alsophila dryopteroides or Cyathea dryopteroides, names that reflect the complex taxonomic history of tree fern classification.

Where Does Forest Alsophila Call Home?

This perennial fern is exclusively native to Puerto Rico, where it has adapted to the island’s unique Caribbean climate and ecosystem conditions. Unfortunately, its geographic distribution is extremely limited, contributing to its precarious conservation status.

A Plant in Crisis: Understanding Its Endangered Status

Important Conservation Alert: Forest alsophila carries a Global Conservation Status of S1, meaning it’s critically imperiled. With typically five or fewer known occurrences and very few remaining individuals (less than 1,000), this species is classified as Endangered in the United States.

If you’re fortunate enough to encounter forest alsophila in cultivation or restoration projects, it’s crucial to ensure any plant material comes from responsible, conservation-approved sources. Never collect from wild populations, as this could push the species closer to extinction.

Ecological Preferences and Habitat

Forest alsophila has adapted to life in Puerto Rico’s wetland environments, earning a classification as a Facultative Wetland species in the Caribbean region. This means it usually thrives in wetland conditions but can occasionally survive in drier areas. This flexibility might have helped the species survive environmental changes, though clearly not enough to prevent its current endangered status.

Why This Fern Matters

Beyond its inherent right to exist, forest alsophila represents:

  • A living link to ancient plant lineages that dominated prehistoric landscapes
  • An important component of Puerto Rico’s unique island biodiversity
  • A reminder of how human activities can impact even the most resilient-seeming species
  • An opportunity for conservation-minded gardeners to support native plant preservation efforts

How You Can Help

While most gardeners won’t have the opportunity to grow forest alsophila due to its rarity and specific needs, you can still support its conservation:

  • Support organizations working to protect Puerto Rican native plants
  • Choose other native fern species for your garden to reduce pressure on wild populations
  • Spread awareness about the importance of plant conservation
  • If you live in Puerto Rico, participate in local habitat restoration projects

Forest alsophila serves as a powerful reminder that even the most ancient and seemingly resilient plants can become vulnerable. By understanding and appreciating species like this critically endangered tree fern, we can better protect the botanical diversity that makes our world so wonderfully complex and beautiful.

Forest Alsophila

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Polypodiales

Family

Cyatheaceae Kaulf. - Tree Fern family

Genus

Alsophila R. Br. - alsophila

Species

Alsophila amintae Conant - forest alsophila

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA