Acanthaceae is a family of dicotyledonous flowering plants in the order Lamiales. The acanthus family includes almost 250 genera and about 2500 species. Most are tropical herbs, shrubs, or twining vines; some are epiphytes. Only a few species are distributed in temperate regions. The four main centres of distribution are Indonesia and Malaysia, Africa, Brazil, and Central America. Representatives of the family can be found in nearly every habitat, including dense or open forests, scrublands, wet fields and valleys, sea coast and marine areas, swamps, and mangrove forests.

23,420 species of vascular plant have been recorded in South Africa, making it the sixth most species-rich country in the world and the most species-rich country on the African continent. Of these, 153 species are considered to be threatened. Nine biomes have been described in South Africa: Fynbos, Succulent Karoo, desert, Nama Karoo, grassland, savanna, Albany thickets, the Indian Ocean coastal belt, and forests.

The 2018 South African National Biodiversity Institute's National Biodiversity Assessment plant checklist lists 35,130 taxa in the phyla Anthocerotophyta (hornworts (6)), Anthophyta (flowering plants (33534)), Bryophyta (mosses (685)), Cycadophyta (cycads (42)), Lycopodiophyta (Lycophytes(45)), Marchantiophyta (liverworts (376)), Pinophyta (conifers (33)), and Pteridophyta (cryptogams (408)).

66 genera are represented in the literature. Listed taxa include species, subspecies, varieties, and forms as recorded, some of which have subsequently been allocated to other taxa as synonyms, in which cases the accepted taxon is appended to the listing. Multiple entries under alternative names reflect taxonomic revision over time.

Acanthodium Genus Acanthodium: Acanthodium angustum Nees, accepted as Blepharis angusta (Nees) T.Anderson, indigenous Acanthodium capense (L.f.) Nees, accepted as Blepharis capensis (L.f.) Pers. indigenous Acanthodium capense (L.f.) Nees var. a Nees, accepted as Blepharis capensis (L.f.) Pers. Acanthodium capense (L.f.) Nees var. b Nees, accepted as Blepharis capensis (L.f.) Pers. Acanthodium capense (L.f.) Nees var. inermis Nees, accepted as Blepharis inermis (Nees) C.B.Clarke Acanthodium capense (L.f.) Nees var. integrifolium Nees, accepted as Blepharis capensis (L.f.) Pers. indigenous Acanthodium capense (L.f.) Nees var. leucographum Nees, accepted as Blepharis capensis (L.f.) Pers. indigenous Acanthodium capense (L.f.) Nees var. villosum Nees, accepted as Blepharis mitrata C.B.Clarke Acanthodium capense (L.f.) Nees var. villosum Nees, accepted as Blepharis capensis (L.f.) Pers. indigenous Acanthodium carduifolium (L.f.) Nees, accepted as Acanthopsis carduifolia (L.f.) Schinz, indigenous Acanthodium dipsaceum E.Mey. accepted as Acanthopsis disperma Nees Acanthodium dispermum E.Mey. accepted as Acanthopsis disperma Nees Acanthodium diversispinum Nees, accepted as Blepharis diversispina (Nees) C.B.Clarke Acanthodium diversispinum Nees var. a Nees, accepted as Blepharis serrulata (Nees) Ficalho & Hiern Acanthodium glabrum Nees, accepted as Acanthopsis glabra (Nees) H.M.Steyn, indigenous Acanthodium glaucum E.Mey. ex Nees, accepted as Acanthopsis glauca (E.Mey. ex Nees) Schinz, indigenous Acanthodium grossum Nees, accepted as Blepharis grossa (Nees) T.Anderson, indigenous Acanthodium hirtinervium Nees, accepted as Blepharis hirtinervia (Nees) T.Anderson, indigenous Acanthodium hoffmannseggianum Nees, accepted as Acanthopsis hoffmannseggiana (Nees) C.B.Clarke, indigenous Acanthodium macrum Nees, accepted as Blepharis macra (Nees) Vollesen Acanthodium marginatum Nees, accepted as Blepharis marginata (Nees) C.B.Clarke Acanthodium plumolosum E.Mey. ex Nees, accepted as Acanthopsis horrida (Nees) Nees, indigenous Acanthodium plumosum E.Mey. accepted as Acanthopsis horrida (Nees) Nees, indigenous Acanthodium serrulatum Nees, accepted as Blepharis serrulata (Nees) Ficalho & Hiern, indigenous Acanthodium sinuatum Nees, accepted as Blepharis sinuata (Nees) C.B.Clarke, indigenous Acanthodium spathulare Nees, accepted as Acanthopsis spathularis (Nees) Schinz, indigenous Acanthodium squarrosum Nees, accepted as Blepharis squarrosa (Nees) T.Anderson, indigenous

Acanthopsis Genus Acanthopsis: Acanthopsis carduifolia (L.f.) Schinz, endemic Acanthopsis carduifolia (L.f.) Schinz var. glabra (Nees) Schinz, accepted as Acanthopsis glabra (Nees) H.M.Steyn, indigenous Acanthopsis carduifolia (L.f.) Schinz var. longearistata Schinz, accepted as Acanthopsis disperma Nees Acanthopsis disperma Nees, indigenous Acanthopsis dispermoides H.M.Steyn, endemic Acanthopsis dregeana H.M.Steyn, endemic Acanthopsis dregeana H.M.Steyn subsp. dregeana, endemic Acanthopsis dregeana H.M.Steyn subsp. longispina H.M.Steyn, endemic Acanthopsis erosa H.M.Steyn, endemic Acanthopsis glabra (Nees) H.M.Steyn, endemic Acanthopsis glandulopalmata H.M.Steyn, endemic Acanthopsis glauca (E.Mey. ex Nees) Schinz, endemic Acanthopsis hoffmannseggiana (Nees) C.B.Clarke, indigenous Acanthopsis horrida (Nees) Nees, endemic Acanthopsis insueta H.M.Steyn, endemic Acanthopsis ludoviciana H.M.Steyn, endemic Acanthopsis nitida H.M.Steyn, endemic Acanthopsis scullyi (S.Moore) Oberm. endemic Acanthopsis spathularis (Nees) Schinz, endemic Acanthopsis tetragona H.M.Steyn, endemic Acanthopsis tetragona H.M.Steyn subsp. pedunculata H.M.Steyn, endemic Acanthopsis tetragona H.M.Steyn subsp. tetragona, endemic Acanthopsis trispina C.B.Clarke, accepted as Acanthopsis horrida (Nees) Nees, endemic Acanthopsis tuba H.M.Steyn, endemic Acanthopsis villosa H.M.Steyn, endemic

Acanthus Genus Acanthus: Acanthus arboreus Forssk. forma albiflorus Fiori, accepted as Acanthus polystachyus Delile Acanthus arboreus Forssk. var. pubescens Thomson ex Oliv. accepted as Acanthus polystachyus Delile Acanthus capensis L.f. accepted as Blepharis capensis (L.f.) Pers. Acanthus carduifolius L.f. accepted as Acanthopsis carduifolia (L.f.) Schinz, indigenous Acanthus carduifolius Thunb. accepted as Acanthopsis carduifolia (L.f.) Schinz, indigenous Acanthus carduifolius Thunb. ß spica villosa E.Mey. accepted as Acanthopsis villosa H.M.Steyn Acanthus flamandii De Wild. accepted as Acanthus polystachyus Delile Acanthus furcatus L.f. accepted as Blepharis furcata (L.f.) Pers. Acanthus glaber E.Mey. accepted as Acanthopsis glabra (Nees) H.M.Steyn, indigenous Acanthus glaucescens E.Mey. accepted as Acanthopsis glauca (E.Mey. ex Nees) Schinz, indigenous Acanthus glaucus E.Mey. accepted as Acanthopsis glauca (E.Mey. ex Nees) Schinz, indigenous Acanthus integrifolius L.f. accepted as Blepharis integrifolia (L.f.) E.Mey. ex Schinz var. integrifolia Acanthus maderaspatensis L. accepted as Blepharis maderaspatensis (L.) Roth Acanthus mollis L. not indigenous, cultivated, naturalised, invasive Acanthus polystachyus Delile, not indigenous, naturalised Acanthus polystachyus Delile var. pseudopubescens Cufod. accepted as Acanthus polystachyus Delile Acanthus procumbens L.f. accepted as Blepharis procumbens (L.f.) Pers. Acanthus pubescens (Thomson ex Oliv.) Engl. accepted as Acanthus polystachyus Delile, not indigenous, naturalised Acanthus spathularis E.Mey. accepted as Acanthopsis spathularis (Nees) Schinz, indigenous Acanthus ugandensis C.B.Clarke, accepted as Acanthus polystachyus Delile

Adhatoda Genus Adhatoda: Adhatoda anagalloides Nees, accepted as Justicia anagalloides (Nees) T.Anderson, indigenous Adhatoda andromeda (Lindau) C.B.Clarke, endemic Adhatoda anselliana Nees, accepted as Justicia anselliana (Nees) T.Anderson Adhatoda betonica (L.) Nees, accepted as Justicia betonica L. indigenous Adhatoda capensis (Thunb.) Nees, accepted as Justicia capensis Thunb. indigenous Adhatoda capensis (Thunb.) Nees var. arenosa Nees, accepted as Justicia debilis (Forssk.) Vahl, indigenous Adhatoda cheiranthifolia Nees, accepted as Justicia betonica L. indigenous Adhatoda densiflora (Hochst.) J.C.Manning, accepted as Justicia natalensis (Nees) T.Anderson, endemic Adhatoda divaricata (Licht. ex Roem. & Schult.) Nees, accepted as Justicia divaricata Licht. ex Roem. & Schult. indigenous Adhatoda duvernoia (Nees) C.B.Clarke, accepted as Justicia adhatodoides (E.Mey. ex Nees) V.A.W.Graham, indigenous Adhatoda eylesiii S.Moore, accepted as Isoglossa eylesii (S.Moore) Brummitt Adhatoda fasciata Nees, accepted as Justicia flava (Vahl) Vahl, indigenous Adhatoda flava (Vahl) Nees, accepted as Justicia flava (Vahl) Vahl, indigenous Adhatoda formosissima Klotzsch, accepted as Anisotes formosissimus (Klotzsch) Milne-Redh. Adhatoda incana (Nees) Nees, accepted as Justicia incana (Nees) T.Anderson, indigenous Adhatoda lupulina Nees, accepted as Justicia betonica L. indigenous Adhatoda matammensis Schweinf. accepted as Justicia matammensis (Schweinf.) Oliv. indigenous Adhatoda mollissima Nees, accepted as Justicia dregei J.C.Manning & Goldblatt, indigenous Adhatoda natalensis Nees, accepted as Justicia natalensis (Nees) T.Anderson, indigenous Adhatoda odora (Forssk.) Nees, accepted as Justicia odora (Forssk.) Lam. indigenous Adhatoda petiolaris Nees, accepted as Justicia petiolaris (Nees) T.Anderson subsp. petiolaris, indigenous Adhatoda protracta (Nees) Nees, accepted as Justicia protracta (Nees) T.Anderson, indigenous Adhatoda thymifolia Nees, accepted as Justicia thymifolia (Nees) C.B.Clarke, indigenous Adhatoda tubulosa E.Mey. ex Nees, accepted as Justicia tubulosa (E.Mey. ex Nees) T.Anderson subsp. tubulosa, indigenous Adhatoda variegata Nees var. pallidior Nees, accepted as Justicia betonica L. indigenous

Angkalanthus Genus Angkalanthus: Angkalanthus transvaalensis A.Meeuse, accepted as Chorisochora transvaalensis (A.Meeuse) Vollesen, indigenous

Anisotes Genus Anisotes: Anisotes formosissimus (Klotzsch) Milne-Redh. indigenous Anisotes rogersii S.Moore, indigenous

Asteracantha Genus Asteracantha: Asteracantha longifolia (L.) Nees, accepted as Hygrophila auriculata (Schumach.) Heine

Asystasia Genus Asystasia: Asystasia atriplicifolia Bremek. endemic Asystasia coromandeliana Nees var. micrantha Nees, accepted as Asystasia gangetica (L.) T.Anderson subsp. micrantha (Nees) Ensermu, indigenous Asystasia gangetica (L.) T.Anderson, indigenous Asystasia gangetica (L.) T.Anderson subsp. micrantha (Nees) Ensermu, indigenous Asystasia mysorensis (Roth) T.Anderson, indigenous Asystasia natalensis C.B.Clarke, accepted as Salpinctium natalense (C.B.Clarke) T.J.Edwards Asystasia pinguifolia T.J.Edwards, accepted as Asystasia gangetica (L.) T.Anderson subsp. micrantha (Nees) Ensermu, indigenous Asystasia retrocarpa T.J.Edwards, indigenous Asystasia schimperi T.Anderson, accepted as Asystasia mysorensis (Roth) T.Anderson, indigenous Asystasia stenosiphon C.B.Clarke, accepted as Salpinctium stenosiphon (C.B.Clarke) T.J.Edwards Asystasia subbiflora C.B.Clarke, endemic Asystasia varia N.E.Br. endemic

Aulojusticia Genus Aulojusticia: Aulojusticia linifolia Lindau, accepted as Justicia linifolia (Lindau) V.A.W.Graham, indigenous

Avicennia Genus Avicennia: Avicennia marina (Forssk.) Vierh. indigenous

Barleria Genus Barleria: Barleria affinis C.B.Clarke, indigenous Barleria affinis C.B.Clarke subsp. affinis, indigenous Barleria alata S.Moore, accepted as Barleria lancifolia T.Anderson subsp. lancifolia Barleria albida Lindau, accepted as Barleria senensis Klotzsch Barleria albi-pilosa Hainz, accepted as Barleria matopensis S.Moore Barleria albostellata C.B.Clarke, indigenous Barleria argillicola Oberm. endemic Barleria auriculata Schumach. accepted as Hygrophila auriculata (Schumach.) Heine Barleria barbata E.Mey. ex C.B.Clarke, accepted as Barleria gueinzii Sond. indigenous Barleria bechuanensis C.B.Clarke, endemic Barleria bolusii Oberm. endemic Barleria bremekampii Oberm. indigenous