"Katie" Ruellia. Ruellia tweediana, Acanthus Family: ( Acanthaceae ), "Katie" Ruellia. Also called: Ruellia brittoniana, Mexican Petunia, Ruellia simplex, or Mexican barrio ruellia. We wish to thank Wikipedia, the free encyclopedia for some of the information on this page. We share images and information with Wikipedia. The flowers of Ruellia tweediana "Katie" are petunia like, however they are more cup shaped and funnel-like than petunias. The plants are erect, 1 - 2 feet tall and they have few branches. The leaves are 6 - 12 inches long, narrow at the base and very short. The blooms are on the top of the plant in clusters of trumpet-shaped flowers. Mexican Petunias prefer full sun but will tolerate some shade (to the sacrifice of some flowering). Flowering on Katie Ruellia occurs from the late spring to mid summer. Ruellia can tolerate abuse and neglect and it is drought tolerant. This variety has pink colored flowers and dark green leaves. This is a very popular landscaping plant in Arizona and it is considered an evergreen shrub. It is classed as a noxious weed in Florida. Other varieties of Ruella come in purple or blue. Quick Notes: Height: Evergreen bush slowly growing to about 36 - 48 inches tall and about 36 - 48 inches wide. Flowers: The flowers are in leaf axils with 2 - 3 inch long funnel-shaped pink flowers. Flowering Time: Mid March - November. Leaves: Linear, lancolate, serrate, prominent purple venation. They are 6 - 12 inches in length and 1/2 - 3/4 inches wide. Under Arizona hot conditions the foliage assumes a metallic blue cast. Stalk: The stems are purple. Found: Native of eastern Mexico, in the state of Veracruz. The USDA claims it is now native to the USA (AL, FL, GA, HI, LA, MS, SC, TX), USA+ (PR, VI). We see it throughout lower elevations in Arizona as a landscape plant. Hardiness: USDA Zone 8a: to -12.2 �C (10 �F) USDA Zone 8b: to -9.4 �C (15 �F) USDA Zone 9a: to -6.6 �C (20 �F) USDA Zone 9b: to -3.8 �C (25 �F) USDA Zone 10a: to -1.1 �C (30 �F) USDA Zone 10b: to 1.7 �C (35 �F) USDA Zone 11: above 4.5 �C (40 �F) Soil pH requirements: 6.1 to 6.5 (mildly acidic) 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline) Sun Exposure: Full Sun Elevation: 0 to 4,900 feet In Arizona. Habitat: Alkaline, well-drained/light soils. Miscellaneous: Flowering Photos Taken March 06, 2006. Arrowhead Ranch, Glendale, Arizona. An ideal xeriscape landscape plant in Arizona.