Bastard pennyroyal (Trichostema dichotomum, Sp. Pl.: 598 (1753))

Family: Lamiaceae

Author: L.

Bibliography: Sp. Pl.: 598 (1753)

Year: 1753

Status: accepted

Rank: species

Genus: Trichostema

Vegetable: False

Observations: SE. Canada to C. & E. U.S.A., Bahamas

Description

The plant commonly known as Bastard pennyroyal is botanically referred to as Trichostema dichotomum. This intriguing species was first chronicled in the mid-18th century, with its formal description appearing in Sp. Pl.: 598 in the year 1753, attributed to the renowned taxonomist Carl Linnaeus.

Bastard pennyroyal is a member of the Lamiaceae family, a diverse and widespread group more familiarly known as the mint family, which also includes many aromatic herbs. This plant embodies the characteristic features of its family with its aromatic foliage and the distinctive structure of its flowers.

Geographically, Trichostema dichotomum has a sizeable natural distribution. It can be found extending from southeastern Canada through central to eastern United States and down to the Bahamas. This range highlights the plant’s adaptability to various climatic conditions, thriving from temperate to subtropical environments.

Bastard pennyroyal is typically found in open, sunny habitats where it can take full advantage of light and space. It is a herbaceous plant known for its small yet striking blue flowers, which are arranged in a dichotomous branching pattern – a distinct trait alluded to in its scientific name. The plant’s growth form and floral arrangement are not just visually appealing; they also play a crucial role in attracting pollinators, thereby sustaining its propagation in the wild.

Despite its relatively low profile in the broader horticultural context, Trichostema dichotomum holds its ground in botanical studies and ecological documentation for its unique characteristics and significant natural range. It is a quiet yet resilient representative of the diverse and ecologically vital mint family, deserving recognition for both its beauty and biological importance.

Common Names

Eng: bastard pennyroyal, blue curls, blue-curls, forked blue-curls, forked bluecurls
Fra: trichostème fourchu
En: Bastard pennyroyal, Forked blue-curls, Blue-curls, Forked bluecurls, Blue curls
Fr: Trichostème fourchu

Synonyms

• Trichostema pilosum (Roth)
• Trichostema dichotomum var. puberulum (Fernald & Griscom)

Distribution

• Alabama (native)
• Arkansas (native)
• Connecticut (native)
• Delaware (native)
• District of Columbia (native)
• Georgia (native)
• Illinois (native)
• Indiana (native)
• Kentucky (native)
• Louisiana (native)
• Maine (native)
• Maryland (native)
• Masachusettes (native)
• Michigan (native)
• Mississippi (native)
• New Hampshire (native)
• New Jersey (native)
• New York (native)
• North Carolina (native)
• Ohio (native)
• Ontario (native)
• Pennsylvania (native)
• Rhode I. (native)
• South Carolina (native)
• Tennessee (native)
• Texas (native)
• Vermont (native)
• Virginia (native)
• West Virginia (native)

Additional Images

Other

Taken Nov 1, 2019 by Diana (cc-by-sa)

Bark

Taken Nov 1, 2019 by Diana (cc-by-sa)

Taken Jan 1, 1900 by EOL − Steve R. Turner (cc-by-nc-sa)

Flower

Taken Sep 26, 2022 by Danielle Goudreau (cc-by-sa)

Taken Oct 9, 2019 by Doug (cc-by-sa)

Taken Oct 9, 2019 by Doug (cc-by-sa)

Taken Sep 10, 2022 by Yelena Bergman (cc-by-sa)

Taken Aug 31, 2020 by Shirley Hutcherson (cc-by-sa)

Leaf

Taken Sep 28, 2021 by Matthew Horrigan (cc-by-sa)

Taken Oct 6, 2022 by Alex Arriaza (cc-by-sa)

Taken Oct 11, 2014 by EOL − Laura Clark (cc-by-nc)

Taken Jan 1, 1900 by EOL − Steve R. Turner (cc-by-nc-sa)

Taken Sep 25, 2010 by EOL − Ron Thomas (cc-by-nc-sa)

Habit

Taken Jan 1, 1900 by EOL − Cooper, G.A. (cc-by-nc-sa)

Taken Jan 1, 1900 by EOL − Cooper, G.A. (cc-by-nc-sa)

Taken Jan 1, 1900 by EOL − Cooper, G.A. (cc-by-nc-sa)

Taken Jan 1, 1900 by EOL − Cooper, G.A. (cc-by-nc-sa)

Taken Sep 24, 2012 by EOL − Mary Keim (cc-by-nc-sa)

© copyright of the Board of Trustees of the Royal Botanic Gardens, Kew.

Fruit

Taken Jan 1, 1900 by EOL − Steve R. Turner (cc-by-nc-sa)

Taken Jan 1, 1900 by EOL − Steve R. Turner (cc-by-nc-sa)

Sources

• WFO (No URL)
• IPNI (No URL)
• GBIF (https://www.gbif.org/species/2926665)
• POWO (http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:286345-2)
• PlantNet (https://identify.plantnet.org/species/the-plant-list/Trichostema dichotomum L.)

Specifications

Growth habit>: Forb/herb

Growth