North America Native Plant

Southern Quillwort

Botanical name: Isoetes flaccida var. alata

USDA symbol: ISFLA

Life cycle: perennial

Habit: grass

Native status: Native to the lower 48 states  

Southern Quillwort: A Rare Aquatic Treasure for Specialized Gardens Meet the southern quillwort (Isoetes flaccida var. alata), one of nature’s most unusual and ancient plants. This isn’t your typical garden flower or shrub – it’s actually a fascinating member of an ancient plant group that’s been around since before dinosaurs ...

Rare plant alert!

Region: Conservation status by state

Status: S3T1T3Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ Subspecies or variety is 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) ⚘ 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 ⚘ Subspecies or variety is 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. ⚘

Southern Quillwort: A Rare Aquatic Treasure for Specialized Gardens

Meet the southern quillwort (Isoetes flaccida var. alata), one of nature’s most unusual and ancient plants. This isn’t your typical garden flower or shrub – it’s actually a fascinating member of an ancient plant group that’s been around since before dinosaurs roamed the Earth! If you’re curious about unique aquatic plants or interested in wetland restoration, this little-known species might just capture your imagination.

What Exactly Is a Southern Quillwort?

Southern quillwort belongs to a group of plants called quillworts, which are neither grasses nor typical flowering plants. Instead, they’re closer relatives to ferns and reproduce through spores rather than seeds. The name quillwort comes from their distinctive appearance – they look like tiny, green quills or grass-like tufts emerging from muddy substrates.

This perennial plant is characterized by its narrow, grass-like leaves that grow directly from a bulbous base. The leaves are typically 2-8 inches long and have a distinctive hollow structure that helps the plant survive in its aquatic environment.

Where Does Southern Quillwort Call Home?

Southern quillwort is native to the southeastern United States, specifically found in Florida and Georgia. This limited geographic distribution makes it quite special – and quite rare.

A Word of Caution: This Plant Is Rare

Here’s something important to know: southern quillwort has a conservation status that indicates it’s quite rare and potentially vulnerable. Before considering adding this plant to any garden or restoration project, it’s crucial to source it only from reputable, ethical suppliers who can verify that their plants were propagated responsibly and not collected from wild populations.

Is Southern Quillwort Right for Your Garden?

Let’s be honest – this isn’t a plant for everyone or every garden. Southern quillwort has very specific needs that make it suitable only for specialized situations:

  • Aquatic gardens: Perfect for shallow water features or bog gardens
  • Wetland restoration projects: Ideal for restoring native aquatic ecosystems
  • Educational gardens: Great for demonstrating plant evolution and ancient plant forms
  • Specialized collections: Appeals to collectors of unusual or rare plants

Growing Conditions and Care

If you’re determined to grow southern quillwort, here’s what you need to know:

  • Water requirements: Needs consistently wet conditions – either shallow standing water or permanently saturated soil
  • Soil type: Prefers muddy, organic-rich substrates
  • Light: Tolerates both full sun and partial shade
  • Climate: Suitable for USDA hardiness zones 8-10
  • pH: Prefers slightly acidic to neutral water conditions

Benefits to Wildlife and Ecosystems

While southern quillwort may not attract butterflies or hummingbirds like flowering plants, it plays an important role in aquatic ecosystems. It provides habitat for small aquatic invertebrates and helps stabilize muddy substrates in wetland areas. Its presence can indicate a healthy, functioning aquatic ecosystem.

How to Identify Southern Quillwort

Look for these key characteristics:

  • Narrow, grass-like leaves emerging directly from the base
  • Leaves are hollow and somewhat rigid
  • Grows in shallow water or very wet soil
  • No visible flowers (remember, it reproduces by spores!)
  • Forms small tufts or clumps

The Bottom Line

Southern quillwort is definitely not your average garden plant. It’s a living piece of evolutionary history that requires very specific conditions and should only be grown with responsibly sourced plants due to its rarity. If you have a pond, bog garden, or wetland restoration project in the appropriate climate zones, and you can source it ethically, this unique plant could be a fascinating addition that showcases the incredible diversity of plant life on our planet.

For most gardeners, however, there are many other native aquatic plants that might be more practical choices for water gardens while still supporting local ecosystems. Consider consulting with local native plant societies or wetland restoration experts if you’re interested in incorporating rare species like southern quillwort into your landscape.

Southern 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 flaccida Shuttlw. ex A. Braun - southern quillwort

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