Synonym(s): Ruellia simplex, Ruellia brittoniana or Mexican Pentunia
Family: Acanthaceae (Acanthus Family)
Duration and Habit: Perennial Herb
This deciduous plant can grow up to 3-4ft. From sping through fall it will have purple, lavender, white, or pink flowers which attract butterflies.
Native Lookalikes: Ruellia nudiflora (violet wild petunia)
violet wild petunia (Ruellia nudiflora)
Ecological Threat: It forms dense stands in the understory of forests, crowding out native plants and altering fire and succession regimes.
Biology & Spread: It produces a significant amount of seeds year-long, which do not require exposure to cold weather (stratification) or mechanical damage (scarification) to germinate. Seeds produce a gel-like substance when wet that enables them to stick to surfaces when they dry. It can also spread by lateral roots.
History: Widely popular in the landscape trade, Britton’s wild petunia (also known as Mexican petunia) has been planted across the SE US.
U.S. Habitat: Its purple flowers and tolerance of different urban landscapes makes it a popular choice for difficult areas, as it can thrive in shade, sun, wet, dry, and poor soil.
U.S. Nativity: Introduced to U.S.
Native Origin: Mexico
U.S. Present: AL, FL, GA, HI, LA, MS, SC, TX
Distribution in Texas: Reports from Austin, Brownsville, Dallas and Houston areas.
Invaders of Texas Map: Ruellia caerulea
EDDMapS: Ruellia caerulea
USDA Plants Texas County Map: Ruellia caerulea
List All Observations of Ruellia caerulea reported by Citizen Scientists
All parts of the plant must be removed, including everything above and below ground. Plan on using a shovel to completely remove the root mass because much of its spread occurs underground.If cultural and mechanical control mechanisms fail to be effective,
Chemical: Glyphosate (2-3%) can successfully control the spread of this invasive plant. Although, homeowners may need to apply 2-3 months later because of the density of its stand.
https://plants.usda.gov/home/plantProfile?symbol=RUCA19
https://plants.ifas.ufl.edu/plant-directory/ruellia-simplex/
https://nwdistrict.ifas.ufl.edu/hort/2017/09/18/an-alternative-to-invasive-ruellia/
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USDA Plants: Ruellia caerulea
Invasive Plant Atlas of the United States: Ruellia caerulea
Bugwood Network Images: Ruellia caerulea