North America Native Plant

Quillwort

Botanical name: Isoetes ×altonharvillii

USDA symbol: ISAL4

Life cycle: perennial

Habit: grass

Native status: Native to the lower 48 states  

Discovering the Rare Hybrid Quillwort: A Wetland Specialist for Dedicated Native Plant Enthusiasts If you’re the type of gardener who gets excited about rare, specialized native plants, then Isoetes ×altonharvillii might just pique your interest. This hybrid quillwort represents one of nature’s more mysterious aquatic plants, quietly thriving in very ...

Discovering the Rare Hybrid Quillwort: A Wetland Specialist for Dedicated Native Plant Enthusiasts

If you’re the type of gardener who gets excited about rare, specialized native plants, then Isoetes ×altonharvillii might just pique your interest. This hybrid quillwort represents one of nature’s more mysterious aquatic plants, quietly thriving in very specific wetland conditions along the Eastern United States.

What Makes This Quillwort Special

Isoetes ×altonharvillii is a perennial quillwort that belongs to an ancient group of plants that have been around since the dinosaurs roamed the Earth. As a hybrid species (indicated by the × in its name), this plant represents a natural cross between two quillwort parent species, making it quite rare in the plant world.

This grass-like plant might not look like much at first glance, but don’t let its humble appearance fool you. Quillworts are living fossils that have survived multiple mass extinctions and continue to play important ecological roles in wetland ecosystems.

Where You’ll Find This Wetland Native

This particular quillwort calls the Mid-Atlantic region home, with documented populations in Delaware and Virginia. Its limited geographic range makes it a true regional specialty plant that represents the unique biodiversity of Eastern coastal wetlands.

A Plant That Lives Life Underwater

Here’s where things get interesting (and challenging) for most gardeners: this quillwort is classified as an Obligate Wetland plant in both the Atlantic and Gulf Coastal Plain region and the Eastern Mountains and Piedmont region. This means it almost always occurs in wetlands and has adapted to life in constantly wet or submerged conditions.

Unlike your typical garden perennial, this plant has evolved to thrive with its roots underwater or in permanently saturated soils. It’s essentially an aquatic plant that most gardeners will never encounter in traditional landscaping.

Should You Try Growing This Rare Quillwort?

Here’s the honest truth: this isn’t a plant for most gardeners. The extreme rarity of Isoetes ×altonharvillii, combined with its very specific wetland requirements, makes it more of a conservation curiosity than a practical garden plant. Here’s what you need to consider:

  • Availability: You’re unlikely to find this plant at your local nursery or even specialized native plant sales
  • Growing conditions: Requires permanent wetland conditions that are difficult to replicate in most residential settings
  • Conservation status: As a rare hybrid, any specimens should come from responsibly sourced, propagated material rather than wild collection
  • Specialized knowledge: Successfully growing aquatic plants like quillworts requires understanding of wetland ecology and water chemistry

Alternative Wetland Plants for Your Garden

If you’re drawn to the idea of growing native wetland plants but want something more accessible, consider these alternatives that can thrive in garden rain gardens or bog gardens:

  • Blue flag iris (Iris versicolor)
  • Swamp milkweed (Asclepias incarnata)
  • Cardinal flower (Lobelia cardinalis)
  • Wild rice (Zizania species)

Appreciating Quillworts in Their Natural Habitat

Rather than attempting to grow this rare hybrid, the best way to appreciate Isoetes ×altonharvillii is to support wetland conservation efforts in Delaware and Virginia. These ancient plants serve as indicators of healthy wetland ecosystems and deserve protection in their natural habitats.

If you’re interested in aquatic gardening, focus on creating habitat for more readily available native wetland plants that can provide similar ecological benefits while being much more suitable for home cultivation. Your local native plant society can help you identify appropriate species for your region and growing conditions.

Sometimes the most responsible way to love a plant is to admire it from afar and ensure its wild populations remain undisturbed for future generations to discover and appreciate.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Atlantic and Gulf Coastal Plain

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Eastern Mountains and Piedmont

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Quillwort

Classification

Group

Quillwort

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision
Division

Lycopodiophyta - Lycopods

Subdivision
Class

Lycopodiopsida

Subclass
Order

Isoetales

Family

Isoetaceae Dumort. - Quillwort family

Genus

Isoetes L. - quillwort

Species

Isoetes ×altonharvillii L.J. Musselman & R.D. Bray [engelmannii × vallida] - quillwort

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