North America Native Plant

Piedmont Mock Bishopweed

Botanical name: Ptilimnium nodosum

USDA symbol: PTNO

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Harperella fluviatilis Rose (HAFL5)  âš˜  Harperella nodosa Rose (HANO)  âš˜  Harperella vivipara Rose (HAVI6)  âš˜  Ptilimnium fluviatile (Rose) Mathias (PTFL)  âš˜  Ptilimnium fluviatile (Rose) Mathias var. viviparum (Rose) Reveal & Broome (PTFLV)  âš˜  Ptilimnium viviparum (Rose) Mathias (PTVI3)   

Piedmont Mock Bishopweed: A Rare Wetland Treasure Worth Protecting If you’re passionate about native plants and wetland conservation, you may have heard whispers about piedmont mock bishopweed (Ptilimnium nodosum). This delicate annual herb is one of those special plants that makes conservation botanists both excited and worried at the same ...

Rare plant alert!

Region: Alabama

Status: S2: 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) ⚘ Uncertain taxonomy: ⚘ 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) ⚘ 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) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘ 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) ⚘

Region: Alabama

Region: Alabama

Region: Alabama

Region: Alabama

Piedmont Mock Bishopweed: A Rare Wetland Treasure Worth Protecting

If you’re passionate about native plants and wetland conservation, you may have heard whispers about piedmont mock bishopweed (Ptilimnium nodosum). This delicate annual herb is one of those special plants that makes conservation botanists both excited and worried at the same time. Let me tell you why this little wetland wonder deserves our attention—and our protection.

What Makes This Plant So Special?

Piedmont mock bishopweed is a charming little forb that belongs to the carrot family. Don’t let its humble appearance fool you—this annual herb produces clusters of tiny white flowers arranged in delicate umbels that seem to float above feathery, finely-divided foliage. It’s the kind of plant that rewards careful observation, revealing its quiet beauty to those who take the time to really look.

As an annual, this plant completes its entire life cycle in just one growing season, making every individual plant precious for continuing the species.

Where Does It Call Home?

This native treasure is found naturally in eight southeastern states: Alabama, Arkansas, Georgia, Maryland, North Carolina, South Carolina, Virginia, and West Virginia. However, don’t expect to stumble across it on your next nature hike—piedmont mock bishopweed is extremely rare throughout its range.

A Plant on the Edge: Understanding Its Rarity

Here’s where things get serious. Piedmont mock bishopweed is federally listed as endangered and is considered globally imperiled. With typically only 6 to 20 known occurrences and very few remaining individuals, this species is hanging on by a thread. In Alabama, it’s even more critically rare with an S1 status, meaning it’s at extreme risk of disappearing from the state entirely.

This rarity status means that you should never collect this plant from the wild. Period. Every individual plant in nature is crucial for the species’ survival.

A Wetland Specialist

One thing that makes piedmont mock bishopweed particularly challenging to grow (and vulnerable in nature) is its very specific habitat requirements. This plant is what botanists call an obligate wetland species, meaning it almost always occurs in wetlands. It needs consistently moist to saturated soils and simply won’t thrive in typical garden conditions.

In its natural habitat, you’ll find it along stream banks, in wet meadows, and in other specialized wetland environments where few other plants can compete.

Should You Grow Piedmont Mock Bishopweed?

This is where I need to give you some tough love. Unless you’re involved in a legitimate conservation effort or restoration project with proper permits and responsibly sourced seeds, you probably shouldn’t attempt to grow this plant. Here’s why:

  • It requires very specific wetland conditions that are difficult to replicate
  • Seeds should only come from established conservation programs
  • Wild collection could harm already vulnerable populations
  • It’s best suited for specialized restoration projects rather than home gardens

If You’re Determined to Help

If you’re passionate about supporting this species, consider these alternatives:

  • Support wetland conservation organizations working on habitat protection
  • Create habitat for other native wetland plants that aren’t as rare
  • Participate in citizen science projects that monitor rare plant populations
  • Advocate for stream and wetland protection in your area

Growing Conditions (For Conservation Projects Only)

For those involved in legitimate restoration efforts, piedmont mock bishopweed requires:

  • USDA Hardiness Zones 6-9
  • Full sun to partial shade
  • Consistently moist to saturated, well-draining soils
  • Neutral to slightly acidic pH
  • Protection from competition with aggressive species

The Bigger Picture

Piedmont mock bishopweed serves as a perfect example of why we need to protect our remaining wetland habitats. These specialized ecosystems support not just rare plants like this one, but also countless insects, birds, amphibians, and other wildlife that depend on clean water and healthy riparian zones.

While you might not be able to grow this particular plant in your garden, you can still make a difference by choosing other native wetland plants for rain gardens and moist areas of your landscape. Consider alternatives like blue flag iris, cardinal flower, or swamp milkweed—beautiful natives that can thrive in cultivation while supporting pollinators and wildlife.

Sometimes the best way to appreciate a rare plant is to protect the wild spaces where it belongs, ensuring that future generations might have the chance to encounter this delicate beauty in its natural home.

Piedmont Mock Bishopweed

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Apiales

Family

Apiaceae Lindl. - Carrot family

Genus

Ptilimnium Raf. - mock bishopweed

Species

Ptilimnium nodosum (Rose) Mathias - piedmont mock bishopweed

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