North America Native Plant

Dwarf False Pennyroyal

Botanical name: Hedeoma nana macrocalyx

USDA symbol: HENAM

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Dwarf False Pennyroyal: Arizona’s Mysterious Native Mint Meet Hedeoma nana macrocalyx, better known as dwarf false pennyroyal – a native Arizona plant that’s as intriguing as it is elusive. This little-known member of the mint family represents one of those fascinating native species that botanists know exists but gardeners rarely ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3T4: Status is uncertain but is somewhere between the following rankings: 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. ⚘ Subspecies or varieties is apparently secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the region or more than 10,000 individuals ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Dwarf False Pennyroyal: Arizona’s Mysterious Native Mint

Meet Hedeoma nana macrocalyx, better known as dwarf false pennyroyal – a native Arizona plant that’s as intriguing as it is elusive. This little-known member of the mint family represents one of those fascinating native species that botanists know exists but gardeners rarely encounter.

A True Arizona Native

Dwarf false pennyroyal is authentically native to the lower 48 states, specifically found growing wild in Arizona. As a true native species, it has evolved alongside local wildlife and climate conditions for thousands of years, making it perfectly adapted to its natural environment.

What Makes This Plant Special

This charming native is classified as a forb – essentially a soft-stemmed, herbaceous plant without woody tissue. Unlike shrubs or trees, dwarf false pennyroyal stays relatively low to the ground with its perennating buds positioned at or below the soil surface. Interestingly, it can behave as either an annual or perennial, adapting its life cycle to local conditions.

A Plant Shrouded in Mystery

Here’s where dwarf false pennyroyal gets particularly fascinating – and frustrating for curious gardeners. This native species has a conservation status of S5T3T4, suggesting it may be uncommon or specialized in its habitat requirements. Unfortunately, detailed information about its appearance, growing habits, and cultivation requirements remains limited in readily available sources.

Should You Grow Dwarf False Pennyroyal?

The short answer is: it’s complicated. While this native Arizona plant would theoretically make a wonderful addition to authentic native gardens, several factors make it challenging for home gardeners:

  • Limited availability in the nursery trade
  • Unclear growing requirements and care instructions
  • Potential rarity concerns requiring responsible sourcing
  • Lack of documented garden performance

If You’re Determined to Try

Should you encounter dwarf false pennyroyal through a reputable native plant society or specialized nursery, here’s what we do know:

  • Source plants only from ethical suppliers who propagate rather than wild-collect
  • Expect it to behave like other Arizona natives – likely preferring well-draining soil and minimal summer water
  • As a forb, it won’t provide structural elements but could add textural interest to native plant gardens
  • Being in the mint family, it may offer aromatic foliage

Native Alternatives to Consider

If you’re drawn to the idea of growing native Arizona mints but can’t locate dwarf false pennyroyal, consider these more readily available alternatives:

  • Desert lavender (Hyptis emoryi) for aromatic foliage
  • Bee balm species native to your region
  • Other Hedeoma species that may be more widely cultivated

The Bottom Line

Dwarf false pennyroyal represents the exciting frontier of native plant gardening – species that are authentically native but remain largely unexplored in cultivation. While it’s not practical for most gardeners right now, plants like this remind us how much we still have to discover about our native flora. Who knows? Maybe someday a dedicated native plant enthusiast will unlock the secrets to growing this Arizona mystery plant, bringing it into wider cultivation where it belongs.

For now, appreciate dwarf false pennyroyal as one of nature’s quiet treasures, thriving in its Arizona homeland and waiting for its moment in the garden spotlight.

Dwarf False Pennyroyal

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Lamiales

Family

Lamiaceae Martinov - Mint family

Genus

Hedeoma Pers. - false pennyroyal

Species

Hedeoma nana (Torr.) Briq. - dwarf false pennyroyal

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