FNPS Plant Database

Piloblephis rigida

pennyroyal
  • Photo by: Shirley Denton, Suncoast Chapter FNPS
  • Photo by: Ginny Stibolt, Ixia Chapter FNPS

Nomenclature

Common Name:

pennyroyal

Synonym(s):

Genus species:

Piloblephis rigida

Family:

Lamiaceae (Labiatae)

Plant Specifics

Form:

shrub

Size:

1-2 ft tall by 1 ft wide

Life Span:

Long-lived perennial

Flower Color:

lavender

Fruit Color:

Phenology:

Evergreen. Blooms all year but most abundantly in spring.

Noted For:

Showy Flowers, Aroma/Showy Fruitsagrance

Landscaping

Recommended Uses:

Wildflower garden, groundcover.

Considerations:

Short-lived: it tends to die back after a few years.

Availability:

FNPS Plant Sales

Propagation:

Light:

Full Sun

Moisture Tolerance:

Always Flooded---------------------------------Extremely Dry

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Not wet but not extremely dry -to- Somewhat long very dry periods

Salt Water Flooding Tolerance:

Unknown

Salt Spray/Salty Soil Tolerance:

Low/no tolerance of salty wind or direct salt spray

Soil or Other Substrate:

Sand

Soil pH:

Acidic

Suitable to Grow In:

9A,9B,10A,10B

USDA zones are based on the average annual extreme minimum winter temperature.

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Vouchered In:

Distribution
Vouchered
Not vouchered
Selected
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No county distribution is available for this plant yet.
Starting…
Map coded by Melissa Fernandez-de Cespedes (Paynes Prairie Chapter)

Ecology

Wildlife:

Pollinators, Butterflies

Attracts butterflies and bees ( Florida Wildflower Foundation Blog ).  Documented bee visitors include  Agapostemoiz splendens, Augochlorella aurata, Dialictus miiziatulus, D. nyinphalis and  Megachile brevis pseudobrevis (Deyrup et al. 2002).

Native Habitats:

Scrubby flatwoods, scrub, dry flatwoods, dry prairie, sandhill, ruderal.

Natural Range in Florida:

Comments:

Ethnobotany:

General Comments:

This is nearly endemic to Florida (there are a few documented occurrences in southeastern Georgia).
FNPS Plant Print

Citations:

BONAP Plant Atlas. (2014). Range Map: Piloblephis rigida. ( https://bonap.net/MapGallery/County/Piloblephis%20rigida.png ). Accessed 2026. Biota of North America Program, Chapel Hill, NC.


Florida Wildflower Foundation. (2025). Flower Friday: Wild Pennyroyal. ( https://www.flawildflowers.org/flower-friday-piloblephis-rigida/ ). Accessed 2026. Florida Wildflower Foundation, Maitland.


Gann, G.D., C.J. Abbott, C.G. Stocking, K.N. Hines, and collaborators. (2001+). Natives For Your Neighborhood. ( https://www.regionalconservation.org/beta/nfyn/plantdetail.asp?tx=Pilorigi ). Accessed 2026. The Institute for Regional Conservation. Delray Beach, Florida.


Haehle, Robert G. and Joan Brookwell. (1999). Native Florida Plants. Gulf Publishing Company. Houston, TX.


Huegel, Craig N. (2012). Native Wildflowers and Other Ground Covers for Florida Landscapes. University Press of Florida, Gainesville.


Nelson, Gil. (2003). Florida's Best Landscape Plants: 200 Readily Available Species for Homeowners and Professionals. University Press of Florida, Gainesville.


Osorio, Rufino. (2001). A Gardener's Guide to Florida's Native Plants. University Press of Florida, Gainesville.


Traas, Pamela. (2001). Gardening for Florida's Butterflies. Great Outdoors Publishing Co., St. Petersburg, FL.


Wunderlin, R. P., B. F. Hansen, A. R. Franck, and F. B. Essig. (1999+). Atlas of Florida Plants. ( https://florida.plantatlas.usf.edu/ ). [S. M. Landry and K. N. Campbell (application development), USF Water Institute.] Institute for Systematic Botany, University of South Florida, Tampa.

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