North America Native Plant

Spike Quillwort

Botanical name: Isoetes prototypus

USDA symbol: ISPR

Life cycle: perennial

Habit: grass

Native status: Native to Canada âš˜ Native to the lower 48 states  

Spike Quillwort: A Rare Aquatic Native Worth Knowing If you’ve ever wandered along the edges of pristine ponds or bogs in the northeastern United States and Atlantic Canada, you might have encountered a curious little plant that looks like underwater grass but isn’t grass at all. Meet the spike quillwort ...

Rare plant alert!

Region: Conservation status by state

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 ⚘

Spike Quillwort: A Rare Aquatic Native Worth Knowing

If you’ve ever wandered along the edges of pristine ponds or bogs in the northeastern United States and Atlantic Canada, you might have encountered a curious little plant that looks like underwater grass but isn’t grass at all. Meet the spike quillwort (Isoetes prototypus), one of nature’s more mysterious and ancient plant species that’s been quietly thriving in our wetlands for millions of years.

What Exactly Is a Spike Quillwort?

Don’t let the name fool you – spike quillwort isn’t related to grasses, despite its grass-like appearance. This fascinating plant belongs to an ancient group called quillworts, which are actually more closely related to ferns than to any flowering plant in your garden. Think of them as living fossils that have been perfecting their aquatic lifestyle since long before flowers even existed!

These perennial plants produce spores instead of seeds and have a unique look that sets them apart once you know what to watch for. Their narrow, cylindrical leaves emerge from an underground stem called a corm, creating tight clusters that can look remarkably like small tufts of grass growing in shallow water.

Where to Find Spike Quillwort

Spike quillwort is native to a relatively small area of northeastern North America, calling home to parts of Canada including New Brunswick and Nova Scotia, as well as portions of Maine and New Hampshire in the United States. This limited range makes every sighting special, as you’re witnessing a plant that has adapted to very specific conditions over thousands of years.

A Wetland Specialist

Here’s where spike quillwort gets really interesting from an ecological perspective. This plant is what scientists call an obligate wetland species, meaning it almost always occurs in wetlands and rarely strays from these watery homes. You’ll typically find it growing in:

  • Shallow margins of acidic ponds and lakes
  • Bog edges and marshy areas
  • Areas with sandy or peaty substrates
  • Waters that remain relatively undisturbed

Why Spike Quillwort Matters (And Why You Probably Shouldn’t Try to Grow It)

Before you get excited about adding this unique native to your water garden, there’s something important you should know: spike quillwort has a conservation status of S2S3, indicating it’s quite rare and potentially vulnerable. This isn’t a plant you’ll find at your local nursery, nor should you attempt to harvest it from the wild.

Instead of trying to cultivate spike quillwort, consider it a special indicator species. Finding it in a wetland tells you that ecosystem is healthy and relatively undisturbed – something to celebrate and protect rather than disturb.

Identifying Spike Quillwort in the Wild

If you’re lucky enough to encounter spike quillwort during your wetland explorations, here’s how to identify it:

  • Look for small clusters of narrow, tube-like leaves growing from a central point
  • Leaves are typically 2-8 inches long and emerge directly from the sediment
  • The plant grows partially or completely submerged in shallow water
  • Individual plants form small, grass-like tufts rather than spreading carpets
  • Found exclusively in acidic, nutrient-poor wetland environments

Supporting Native Wetland Plants Instead

While you can’t (and shouldn’t) grow spike quillwort in your garden, you can support similar wetland ecosystems by creating bog gardens or rain gardens with other native aquatic plants. Consider alternatives like native sedges, rushes, or water lilies that are more readily available and better suited to cultivation.

The best way to appreciate spike quillwort is to protect the wetland habitats where it naturally occurs. Support conservation efforts, practice Leave No Trace principles when visiting wetlands, and help maintain the water quality these rare plants depend on.

A Living Connection to Ancient Times

Every time you spot a spike quillwort, you’re looking at a survivor from an ancient world. These remarkable plants remind us that some of nature’s most interesting species aren’t the showiest or most garden-worthy – sometimes they’re the quiet specialists that have found their perfect niche and stuck with it for millions of years.

So the next time you’re exploring northeastern wetlands, keep an eye out for those unassuming grass-like tufts in the shallows. You might just be looking at one of nature’s most successful and enduring designs – the humble but remarkable spike quillwort.

Spike 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 prototypus D.M. Britton - spike quillwort

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