Ruellia simplex

Ruellia simplex C. Wright, Anales Acad. Ci. Med. Habana 6: 321. 1870 ; R. brittoniana Leonard, J. Wash. Acad. Sci. 31: 96. 1941; Baily, Man. Cult. Pl. 918. 1949; Hortus. Third, 987. 1976; Sharma & Bir, Fl. Patiala 139. 1978; Malik & Ghafoor, Fl. Pak. @ eFloras.org p. 64.

An erect to spreading, perennial undershrub, ca.1 m tall, almost glabrous or sparsely hairy at the base of petiole and stem. Stem 4-angled, nodes swollen. Leaves opposite, simple, sessile or petiolate, petiole 10-12 mm long, pulvinate and pubescent at the base; leaf blade linear, linear-lanceolate or lanceolate, 6-30 cm x 5-19 mm, whitish-veined above, base long attenuate, margin entire or somewhat undulate, apex acute. Flowers bisexual, slightly zygomorphic, hypogynous, metallic purple, in lax, terminal, leafy corymbiform panicle; pedicel up to 1.5 cm long; bracts linear, 1-2 cm long, acute; bracteoles absent. Calyx deeply 5-partite, glandular on outside; tube ca. 3 mm long; lobes ca. 10 mm long, linear or lanceolate. Corolla metallic purple, glabrous, funnelform, ca. 5-6 cm long, glabrous outside; tube 3.8-4.5 cm long, ventricose, basal 1.3-1.5 cm long tube narrow, cylindrical, ampliated above for 2.5-3 cm long; limb 1-1.5 cm long, spreading, slightly 2-lipped, upper lip 2-lobed and lower 3-lobed, lobes equal to subequal, obovate to somewhat rounded, with margin somewhat crenate. Stamens 4, all fertile, didynamous, included; filaments inserted in tube below throat and basally united in pairs, 8-11 mm long, glabrous; anthers oblong, ca. 3 mm long, bithecous, thecae oblong, parallel, equal, muticous. Carpels 2, syncarpous; ovary glandular, hairy near the apex, bilocular, many ovules in each loculus; style ca. 2 cm long, filiform, disc below the ovary. Capsule ellipsoid, compressed, 1.8-2.2 cm long and ca. 3 mm broad, glabrous, apically pointed, 12-14 seeded, retinacula present. Seeds orbicular, ca. 2.5 mm across, brown.

Flowering and Fruiting: August - November
Common Names: Britton's Wild Petunia, Mexican Petunia, Mexican Bluebell, Desert Petunia

Ruellia simplex - Cultivar with pink flowers: Dwarf version forming 20-30 cm tall clumps. Rest morphology of the plant, flower and fruit nearly similar to that of Desert Petunia with purple flowers.