NPSOT Logo
npsot_bluebonnet_full_color

False pennyroyal

Trichostema brachiatum

Other common name(s):

Fluxweed

Family:

Lamiaceae (Mint Family)

Plant Ecoregion Distribution Map

Edwards Plateau, Texas Blackland Prairies
Balcones Canyonlands, Edwards Plateau Woodland
Northern Blackland Prairie

Plant Characteristics

Growth Form

Herbaceous

Height

.75
to
2
ft.

Spread

.5
to
1
ft.

Leaf Retention

Deciduous

Lifespan

Annual

Habitat and Care Requirements

Soil Type(s)

Sand, Rocky, Limestone, Caliche, Calcareous

Light Requirement

Part Shade

Water Requirement

Low

Native Habitat

Grassland, Woodland

Bloom and Attraction

Bloom Color

Pink, Blue, Purple

Bloom Season

Summer, Fall

Seasonal Interest

Pollen, Flowers

Wildlife Benefit

Bees

Maintenance

Will re-seed easily. Thin and transplant as needed. Grows in thin-soil areas of upland prairies, streambanks, gravel bars, roadsides; often on calcareous substrates. Somewhat uncommon in Texas, although common where found. Propagation: Seed.

Comments

Blooms July-October. Ascending to erect stems. Small, narrowly oblong leaves, densely pubescent and somewhat aromatic. Tiny, inconspicuous, blue flowers grow from the axis of the leaf. This plant has sometimes been lumped together with Trichostem dichotumum, but should be considered separate species. Attracts bees.
Previous Scientific Name(s): Synonyms: Isanthus brachiatus, Isanthus brachiatus var. linearis, Tetraclea viscida

References

1) https://www.prairiemoon.com/isanthus-brachiatus-false-pennyroyal 2) https://www.wildflower.org/plants/result.php?id_plant=TRBR5 3) https://itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=32372#null 4) https://bonap.net/Napa/TaxonMaps/Genus/County/Trichostema 5) R. Kevan Schoonover McClelland, 2022, Studies in the Genus Trichostema Gronov. p 192, 200-201, 251 6) George M. Diggs, Jr., Barney Lipscomb, Robert J. O’Kennon,1999, Shinners & Mahler’s Illustrated Flora of North Central Texas, p783 7) https://portal.torcherbaria.org/portal/taxa/index.php?taxon=Trichostema+coeruleum&formsubmit=Search+Terms, 8) https://www.missouriplants.com/Trichostema_brachiatum_page.html