North America Native Plant

Southern Quillwort

Botanical name: Isoetes flaccida var. flaccida

USDA symbol: ISFLF

Life cycle: perennial

Habit: grass

Native status: Native to the lower 48 states  

Southern Quillwort: An Ancient Aquatic Wonder for Your Water Garden Meet the southern quillwort (Isoetes flaccida var. flaccida), one of nature’s most fascinating living fossils! This quirky little aquatic plant might not win any beauty contests, but it’s been quietly thriving in southeastern waters for millions of years. If you’re ...

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: An Ancient Aquatic Wonder for Your Water Garden

Meet the southern quillwort (Isoetes flaccida var. flaccida), one of nature’s most fascinating living fossils! This quirky little aquatic plant might not win any beauty contests, but it’s been quietly thriving in southeastern waters for millions of years. If you’re looking to add something truly unique to your water garden or bog, this ancient wonder deserves a closer look.

What Exactly Is a Southern Quillwort?

Don’t let the name fool you – southern quillwort isn’t actually related to grasses at all! This perennial belongs to an ancient group of plants called quillworts, which are living remnants from the age of dinosaurs. Think of it as nature’s time capsule, still doing its thing in shallow waters across the Southeast.

The plant gets its name from its distinctive quill-like leaves that emerge from an underground base, creating small tufts that look remarkably like underwater porcupine quills. These grass-like structures are actually quite primitive compared to modern flowering plants, reproducing through spores rather than seeds or flowers.

Where Does Southern Quillwort Call Home?

This native beauty is naturally found throughout Alabama, Florida, and Georgia, where it quietly inhabits shallow waters, pond edges, and seasonally flooded areas. As a true native of the southeastern United States, it’s perfectly adapted to the region’s climate and water conditions.

Important Conservation Note

Here’s something crucial to know: southern quillwort has a conservation status that suggests it may be uncommon or vulnerable in parts of its range. If you’re interested in adding this plant to your water feature, please make sure you source it responsibly from reputable native plant nurseries. Never collect it from the wild!

Is Southern Quillwort Right for Your Garden?

This unique plant is definitely not for every gardener, but it can be perfect for the right situation. Here’s what you need to know:

The Good:

  • Adds authentic native character to water gardens
  • Extremely low maintenance once established
  • Fascinating conversation starter for plant enthusiasts
  • Supports local ecosystem biodiversity
  • Thrives in USDA zones 8-10

The Challenges:

  • Requires permanent shallow water or constantly saturated soil
  • Not particularly showy or ornamental
  • Can be difficult to source due to its specialized nature
  • Limited appeal for traditional landscaping

Perfect Garden Settings

Southern quillwort shines in specialized aquatic environments:

  • Native plant water gardens
  • Bog gardens and wetland restorations
  • Shallow pond edges
  • Rain gardens with permanent water features
  • Educational or conservation-focused landscapes

Growing Tips for Success

If you decide to give southern quillwort a try, here’s how to keep it happy:

Water Requirements: This plant absolutely must have shallow water or permanently saturated soil. Think pond edge rather than typical garden bed – it’s essentially an aquatic plant that can tolerate some variation in water levels.

Soil Preferences: Muddy, organic-rich substrates work best. The plant naturally grows in soft, silty bottoms of ponds and seasonal pools.

Light Needs: Partial to full sun, though it can tolerate some shade, especially in hotter climates.

Maintenance: Once established, southern quillwort is remarkably low-maintenance. Just ensure consistent water levels and you’re good to go!

How to Identify Southern Quillwort

Spotting this plant in the wild (or confirming what you’ve planted) is straightforward once you know what to look for:

  • Small tufts of thin, quill-like leaves emerging from water or mud
  • Leaves are typically 2-6 inches tall
  • No visible flowers – remember, this ancient plant reproduces via spores
  • Often found in groups or colonies in shallow water
  • Leaves may be somewhat translucent and delicate-looking

The Bottom Line

Southern quillwort isn’t going to replace your favorite flowering perennials, but for the right gardener with the right water feature, it’s an absolutely fascinating addition. If you’re passionate about native plants, conservation, or simply love having something completely unique in your garden, this ancient survivor might be exactly what you’re looking for.

Just remember to source it responsibly and give it the aquatic environment it craves. Your southern quillwort will reward you with a living piece of natural history that’s been perfecting its survival strategy for millions of years!

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