North America Native Plant

Old World Adderstongue

Botanical name: Ophioglossum pendulum

USDA symbol: OPPE

Life cycle: perennial

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Hawaii âš˜ Non-native, reproduces and persists in the wild in the lower 48 states âš˜ Native to Pacific Basin excluding Hawaii  

Old World Adderstongue: The Tiny Fern That’s Nothing Like You’d Expect When most people think of ferns, they picture those lush, feathery fronds cascading from hanging baskets or carpeting forest floors. But the Old World adderstongue (Ophioglossum pendulum) throws all those expectations out the window. This perennial fern is so ...

Old World Adderstongue: The Tiny Fern That’s Nothing Like You’d Expect

When most people think of ferns, they picture those lush, feathery fronds cascading from hanging baskets or carpeting forest floors. But the Old World adderstongue (Ophioglossum pendulum) throws all those expectations out the window. This perennial fern is so small and simple that you might walk right past it without realizing you’ve encountered one of nature’s more unusual botanical specimens.

What Exactly Is Old World Adderstongue?

Don’t let the name fool you – this isn’t some exotic flowering plant. Old World adderstongue belongs to an ancient family of ferns that have been around for millions of years. Instead of the typical divided, feathery fronds we associate with ferns, this little guy sports simple, tongue-shaped leaves that barely reach a few inches tall. It’s like nature decided to create the minimalist version of a fern.

The most distinctive feature is its spore-bearing spike that extends above the simple leaf blade, giving it that characteristic tongue appearance. This reproductive structure is what earned it the adderstongue moniker, though it has nothing to do with actual snakes.

Where Does It Call Home?

This fern is native to tropical regions of the Old World, including parts of Africa, Asia, and various Pacific islands. However, it’s established itself as a non-native resident in several U.S. locations including Florida, Hawaii, Guam, and Palau. While it reproduces on its own in these areas, it’s not currently listed as invasive.

Is It Worth Having in Your Garden?

Here’s the honest truth: Old World adderstongue isn’t going to win any beauty contests or create stunning landscape displays. Its appeal lies squarely in the realm of botanical curiosity. If you’re the type of gardener who gets excited about unusual plant forms and ancient lineages, this might intrigue you. For everyone else? There are probably better options.

Growing Conditions and Care

If you’re determined to try growing this unusual fern, you’ll need to recreate its preferred tropical conditions:

  • High humidity (think greenhouse levels)
  • Consistently moist, well-draining soil
  • Filtered shade or low light conditions
  • Warm temperatures year-round (USDA zones 10-12 only)
  • Protection from wind and direct sunlight

This fern is definitely not low-maintenance. It requires the kind of consistent care and specific conditions that make it better suited for serious collectors or specialty botanical gardens rather than typical home landscapes.

Better Native Alternatives

Since Old World adderstongue isn’t native to most of the continental United States and requires very specific growing conditions, consider these native fern alternatives that might better suit your garden:

  • Christmas fern (Polystichum acrostichoides) – hardy and evergreen
  • Maidenhair fern (Adiantum pedatum) – delicate and beautiful
  • Royal fern (Osmunda regalis) – impressive size and fall color
  • Sensitive fern (Onoclea sensibilis) – great for wet areas

These native options will provide much more visual impact, support local ecosystems, and are generally easier to grow in most American gardens.

The Bottom Line

Old World adderstongue is one of those plants that’s more interesting to read about than to actually grow. Unless you’re developing a specialized collection of unusual ferns or have a particular fascination with ancient plant lineages, your garden time and energy are probably better invested in native ferns that will thrive in your local conditions while supporting native wildlife. Sometimes the most exotic isn’t necessarily the most rewarding!

Old World Adderstongue

Classification

Group

Fern

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Pteridophyta - Ferns

Subdivision
Class

Filicopsida

Subclass
Order

Ophioglossales

Family

Ophioglossaceae Martinov - Adder's-tongue family

Genus

Ophioglossum L. - adderstongue

Species

Ophioglossum pendulum L. - Old World adderstongue

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