Ruellia simplex

Common Name: Mexican petunia

Family: Acanthaceae

Common Synonyms: Ruellia brittoniana, R. tweediana

USDA Hardiness Zone: 8a-11

Growth Habit: Perennial herb

Origin: Mexico, Western South America, Antilles

FISC Category: 1

FDACS Listed Noxious Weed: No

Introduction Date: 1940s

IFAS Assessment:

• North: INVASIVE
• Central: INVASIVE
• South: INVASIVE

Description

Perennial herb, to 1 m tall. Stems green or purple. Leaves dark green, opposite, lance-shaped, about 15-30 cm long and 1-2 cm wide, veins prominent below, margins smooth or wavy. Flowers pedunculate, trumpet shaped, 4-8 cm in diameter, solitary or borne in clusters at the tips of the stems, usually purple, but white and pink forms exist. Fertile forms have cylindrical capsules containing 4-28 seeds. Capsules have explosive dehiscence with seeds spreading long distances.

Habitat

Wide variety of habitats, but produces more capsules in wet habitats

Comments

Seeds produce a gel-like substance when wet that enables them to stick to surfaces when they dry. Seeds can germinate at high rates in both light and dark conditions. Stands of Mexican-petunia can also spread via underground rhizomes.

Control Methods

• Manual: Mechanical: Dig up entire plant including root system.
• Chemical: A single foliar treatment of 2% Glyphosate 41.0% L can reduce cover. A follow-up treatment 2-3 months later may be needed (IFAS).
• Biological: NA

Control Notes

NA

References

Dave's Garden. 2014. PlantFiles: Mexican petunia, Ruellia tweediana. http://davesgarden.com/guides/pf/go/1428/. Accessed on June 20, 2014.

Langeland, K.A., H.M. Cherry, C.M. McCormick, K.C. Burks. 2008. Identification and Biology of Non-Native Plants in Florida's Natural Areas-Second Edition. IFAS Publication SP 257. University of Florida, Gainesville, Florida.