North America Native Plant

Louisiana Quillwort

Botanical name: Isoetes louisianensis

USDA symbol: ISLO

Life cycle: perennial

Habit: grass

Native status: Native to the lower 48 states  

Louisiana Quillwort: A Rare Aquatic Wonder for Specialized Gardens Meet the Louisiana quillwort (Isoetes louisianensis), one of nature’s more mysterious aquatic plants that most gardeners have never heard of. This unique little plant isn’t your typical garden variety – it’s actually a living fossil that’s been around since before the ...

Rare plant alert!

Region: Louisiana

Status: S2S3: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ 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: Louisiana

Region: Louisiana

Louisiana Quillwort: A Rare Aquatic Wonder for Specialized Gardens

Meet the Louisiana quillwort (Isoetes louisianensis), one of nature’s more mysterious aquatic plants that most gardeners have never heard of. This unique little plant isn’t your typical garden variety – it’s actually a living fossil that’s been around since before the dinosaurs, and it’s facing some serious challenges in the wild today.

What Exactly is a Louisiana Quillwort?

Don’t let the name fool you – Louisiana quillwort isn’t related to grasses at all, despite its grass-like appearance. It’s actually a type of lycopod, a primitive plant that reproduces through spores rather than seeds or flowers. Think of it as a tiny aquatic fern that decided to cosplay as grass!

This perennial plant produces clusters of quill-like leaves that emerge from shallow water or saturated soil, creating small tufts that look remarkably like underwater porcupine quills. The leaves are typically green and can range from a few inches to about a foot tall, depending on growing conditions.

Where Does Louisiana Quillwort Call Home?

As its name suggests, Louisiana quillwort is native to the southeastern United States, specifically found in Louisiana and Mississippi. This plant is a true Southern belle, adapted to the warm, wet conditions of the Gulf Coastal Plain region.

A Plant in Peril: Rarity Status

Here’s where things get serious – Louisiana quillwort is endangered in Louisiana and has a global conservation status that puts it in the at risk category. This means it’s becoming increasingly rare in the wild, making it a plant that deserves our attention and protection.

If you’re considering adding this unique species to your garden, it’s crucial to source it responsibly from reputable native plant nurseries that don’t collect from wild populations. Never collect plants from their natural habitat!

Is Louisiana Quillwort Right for Your Garden?

Louisiana quillwort isn’t for everyone – it’s definitely a specialist plant with very specific needs. Here’s what you need to know:

Perfect Garden Settings

  • Bog gardens and wetland areas
  • Water gardens with shallow areas
  • Rain gardens that stay consistently moist
  • Native plant restoration projects
  • Educational or conservation gardens

Growing Conditions

This plant is classified as an obligate wetland species, which means it almost always needs to be in or near water. Think of it as the plant equivalent of a fish – it’s just not happy unless its feet are wet!

  • Consistently wet to saturated soil or shallow standing water
  • Full sun to partial shade
  • USDA hardiness zones 8-10
  • Acidic to neutral soil pH

Wildlife and Ecological Benefits

While Louisiana quillwort might not attract butterflies or hummingbirds like flashier native plants, it plays an important role in wetland ecosystems. It helps stabilize soil in wet areas and provides habitat for small aquatic creatures and insects that are part of the broader food web.

How to Identify Louisiana Quillwort

If you’re lucky enough to spot Louisiana quillwort in the wild (remember, look but don’t touch!), here’s what to look for:

  • Small tufts of narrow, grass-like leaves emerging from water or wet soil
  • Leaves are typically 4-12 inches long and very narrow
  • Plants grow in small clusters or colonies
  • Found in shallow water, wet ditches, or seasonally flooded areas
  • No flowers – the plant reproduces via spores produced in specialized structures at the base of the leaves

The Bottom Line

Louisiana quillwort is a fascinating plant that represents millions of years of evolutionary history, but it’s not a beginner’s plant by any stretch. If you have the right conditions – namely, a consistently wet area in your landscape – and can source it responsibly, it’s a wonderful way to support native plant conservation and add a truly unique element to your garden.

For most gardeners, however, there are more accessible native wetland plants that might better suit their needs. Consider alternatives like native sedges, rushes, or other regional wetland species that are more readily available and easier to establish.

If you do decide to grow Louisiana quillwort, you’ll be joining the ranks of conservation-minded gardeners helping to preserve one of nature’s most ancient plant lineages. Just remember – with great botanical power comes great responsibility!

Louisiana 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 louisianensis Thieret - Louisiana quillwort

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