The Geraniales are a small order of flowering plants, in the rosid subclade of eudicots. The largest family in the order is Geraniaceae with over 800 species. In addition, the order includes the smaller Francoaceae with about 40 species. Most Geraniales are herbaceous, but there are also shrubs and small trees.

Flower morphology of the Geraniales is rather conserved. They are usually perfectly pentamerous and pentacyclic without fused organs besides the carpels of the superior gynoecium. The androecium is obdiplostemonous. Only a few genera are tetramerous (Francoa, Tetilla, Melianthus). In some genera some stamens (Pelargonium) or a complete whorl of stamens are reduced (Erodium, Melianthus). In the genera Hypseocharis and Monsonia there are 15 instead of the usual ten stamens. Most genera bear nectariferous flowers.[1] The nectary glands are formed by the receptacle and are localised at the bases of the antesepalous stamens.[1][2]

The anthophytes are a grouping of plant taxa bearing flower-like reproductive structures. They were formerly thought to be a clade comprising plants bearing flower-like structures. The group contained the angiosperms - the extant flowering plants, such as roses and grasses - as well as the Gnetales and the extinct Bennettitales.[3]

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.[4] 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.[5]

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)).[6]

Two families 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.

Geraniaceae

Family: Geraniaceae,[6]

Erodium

Genus Erodium[6]

Geraniospermum

Genus Geraniospermum[6]

Geranium

Genus Geranium[6]

Hoarea

Genus Hoarea[6]

Monsonia

Genus Monsonia[6]

Pelargonium

Genus Pelargonium[6]

Sarcocaulon

Genus Sarcocaulon[6]

Seymouria

Genus Seymouria[6]

Melianthaceae

Family: Melianthaceae,[6]

Bersama

Genus Bersama[6]

Greyia

Genus Greyia[6]

Melianthus

Genus Melianthus[6]

References

  1. ^ a b Jeiter, Julius; Weigend, Maximilian; Hilger, Hartmut H. (1 February 2017). "Geraniales flowers revisited: evolutionary trends in floral nectaries". Annals of Botany. 119 (3): 395–408. doi:10.1093/aob/mcw230. ISSN 0305-7364. PMC 5314648. PMID 28025289.
  2. ^ Jeiter, Julius; Hilger, Hartmut H; Smets, Erik F; Weigend, Maximilian (10 November 2017). "The relationship between nectaries and floral architecture: a case study in Geraniaceae and Hypseocharitaceae". Annals of Botany. 120 (5): 791–803. doi:10.1093/aob/mcx101. ISSN 0305-7364. PMC 5691401. PMID 28961907.
  3. ^ Doyle, J. A.; Donoghue, M. J. (1986). "Seed plant phylogeny and the origin of the angiosperms - an experimental cladistic approach". Botanical Review. 52 (4): 321–431. doi:10.1007/bf02861082.
  4. ^ Butler, Rhett A. (1 July 2019). "Total number of plant species by country". Mongabay. Retrieved 21 July 2019.
  5. ^ "Vegetation of South Africa". PlantZAfrica.com. SA National Biodiversity Institute. Retrieved 24 July 2019.
  6. ^ a b c d e f g h i j k l m n "species_checklist_20180710.csv". South African National Biodiversity Institute. Retrieved 27 September 2020.
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