Description:

• Annual or perennial herbs, undershrubs, shrubs or trees, often aquatic or semi-aquatic
• Leaves opposite-decussate, sometimes whorled, spirally arranged or alternate, simple, entire; stipules (0)2-10 or more
• Flowers bisexual, usually regular, homo-, di- or trimorphic, 4-6-merous, solitary (Rotala and Heimia) or variously arranged in lax or condensed, sessile or pedunculate cymes often subtended by enlarged folded bracts (Nesaea), or flowers in much-branched panicles (Galpinia)
• Calyx lobed; tube shallow, campanulate or cylindrical; lobes valvate, often with minute to long-cornate appendages alternating with lobes
• Petals 0 or as many as calyx lobes, free, arising near or on rim of calyx tube, alternating with calyx lobes, membranous and usually caducous, narrowing towards base, often crumpled in bud, white, pink, purple, yellow or deep orange
• Stamens arising near base of calyx tube, fewer, equal to or twice as many as calyx lobes, if twice as many then of two different lengths; anthers 2-thecous, dorsifixed
• Ovary superior, incompletely (1)2-6-locular; ovules many, axile or on septa; style simple, sometimes very short; stigma capitate or acute (Galpinia)
• Fruit a capsule, dehiscence varied

Nomenclature:

• Lythraceae
  • Schlechtendal: 346 (1827)
  • Sonder: 514 (1862) under Lythrariae
  • Koehne: 241 (1903)
  • Pohnert & Roessler: 1 (1966)
  • Webb: 301 (1968)
  • Fernandes: 276 (1978)
  • Cook: 9 (1979)
  • Fernandes: 7 (1980)
  • Immelman: 35 (1991)
  • Graham et al.: 435 (1998)

Distribution & Notes:

• Global: Genera 25, species 550, ± cosmopolitan, mainly in warm regions; many aquatic or marsh-loving species
• Southern Africa: Genera 6 (4 indigenous, 2 exotic), species 44

References:

• COOK, C.D.K. 1979. Revision of the genus Rotala. Boissiera 29
• FERNANDES, A. 1978. Lythraceae. Flora zambesiaca 4
• FERNANDES, A. 1980. Nesaea Commers. ex Juss. Flora de Moçambique 73
• GRAHAM, S.A., THORNE, R.F. & REVEAL, J.L. 1998. Validation of subfamily names in Lythraceae. Taxon 47
• IMMELMAN, K.L. 1991. Synopsis of the genera Nesaea and Ammannia (Lythraceae) in southern Africa. Bothalia 21
• KOEHNE, E. 1903. Heimia. Das Pflanzenreich Heft 17
• POHNERT, H. & ROESSLER, H. 1966. Lythraceae. Prodromus einer Flora von Südwestafrika 95
• SCHLECHTENDAL, D.F.L. VON. 1827. Heimia. Linnaea 2
• SONDER, O.W. 1862. Lythrarieae. Flora capensis 2
• WEBB, D.A. 1968. Lythrum L. Flora europaea 2

Resources:

• Key to Lythraceae genera

• Lythraceae genera: