Description :

• Shrubs, undershrubs or herbs, with taproot or woody rootstock
• Leaves entire or slightly crenate
• Inflorescence terminal or axillary, thyrses, dichasial cymes or solitary flowers; bracteoles 2, spatulate-elliptic or narrowly oblong, ± as long as calyx
• Calyx ± 2-lipped; with 2 segments free nearly to base and 3 teeth connate nearly to middle; tube shorter than lobes
• Corolla regular, subregular or 2-lipped; lobes 5, obovate; aestivation contorted; tube longer than lobes, cylindric below
• Androecium : fertile stamens 4, didynamous; filaments arising in pairs, ± in middle of corolla tube, slightly exserted, linear; anthers 2-thecous; thecae parallel, muticous; staminodes 0
• Pollen spheroidal, 3-porate; surface with large reticulations
• Disc annular
• Gynoecium : ovary with 3-8 ovules in each locule; style terete; style branch 1; ventral lobe expanded
• Capsule subcylindric, elliptic or clavate, usually perfecting more than 4 seeds, estipitate, with inelastic placental bases
• Seeds compressed, discoid, with hygroscopic hairs restricted to rim; rest of surface smooth
• x = 17 (11, 16)

Nomenclature:

• Ruellia L.
  • Linnaeus: 634 (1753)
  • Clarke: 11 (1901)
  • Meyer: 63 (1968)
• Dinteracanthus C.B.Clarke ex Schinz
  • Schinz: 416 (1915)

Distribution & Notes:

• Global : Species ± 150, America, Africa, Asia and Australia
• Southern Africa : Species ± 15, Namibia, Botswana, Swaziland and widespread mainly in northern and eastern provinces of South Africa