The Aizoaceae (), or fig-marigold family, are a large family of dicotyledonous flowering plants containing 135 genera and about 1,800 species. Several genera are commonly named ice plants or carpet weeds. The Aizoaceae are also referred to as vygies in South Africa. Some of the unusual Southern African genera—such as Conophytum, Lithops, Titanopsis, and Pleiospilos (among others)—resemble gemstones, rocks, or pebbles, and are sometimes called living stones or mesembs (short for mesembryanthemums).

Description

thumb|[[Mesembryanthemum guerichianum seedling, showing the epidermal bladder cells that inspired the name "ice plant"]]

thumb|right| Pronunciation of the South African colloquial name, Vygie, for Aizoaceae

The family Aizoaceae is widely recognised by taxonomists. It once went by the botanical name "Ficoidaceae", now disallowed. The APG II system of 2003 (unchanged from the APG system of 1998) also recognizes the family, and assigns it to the order Caryophyllales in the clade core eudicots. The APG II system also classes the former families Mesembryanthemaceae <small>Fenzl</small>, Sesuviaceae <small>Horan.</small> and Tetragoniaceae <small>Link</small> under the family Aizoaceae.

The common Afrikaans name "vygie" meaning "small fig" refers to the fruiting capsule, which resembles the true fig. Glistening epidermal bladder cells give the family its common name "ice plants".

Most fig-marigolds are herbaceous, rarely somewhat woody, with sympodial growth and stems either erect or prostrate. Leaves are simple, opposite or alternate, and more or less succulent with entire (or rarely toothed) margins. Flowers are perfect in most species (but unisexual in some), actinomorphic, and appear singularly or in few-flowered cymes developing from the leaf axils. Sepals are typically five (3–8) and more or less connate (fused) below. True petals are absent. However, some species have numerous linear petals derived from staminodes. The seed capsules have one to numerous seeds per cell and are often hygrochastic, dispersing seeds by "jet action" when wet. Much of the Aizoaceae's diversity is found in the Greater Cape Floristic Region, which is the most plant-diverse temperate region in the world. A few species are found in Australia and the Central Pacific area.

Carpobrotus is found as an introduced species on the western coast of the United States, New Zealand, the Mediterranean coast of Europe and the southern coast of Brazil.

Evolution

The radiation of the Aizoaceae, specifically the subfamily Ruschioideae, was one of the most recent among the angiosperms, occurring 1.13–6.49 million years ago. It is also one of the fastest radiations ever described in the angiosperms, with a diversification rate of about 4.4 species per million years. This diversification was roughly contemporaneous with major radiations in two other succulent lineages, Cactaceae and Agave.

The family includes many species that use crassulacean acid metabolism as pathway for carbon fixation. Some species in the subfamily Sesuvioideae instead use carbon fixation, which might have evolved multiple times in the group.

Taxonomy

thumb|right|[[Mesembryanthemum cordifolium or rock rose]]

Because of the hyperdiversity of the Aizoaceae and the young age of the clade, many generic and species boundaries are uncertain.

  • Acrosanthes <small>Eckl. & Zeyh.</small>

Subfamily Aizooideae

Genera:

  • Aizoanthemopsis <small>Klak</small>
  • Aizoanthemum <small>Dinter ex Friedrich</small>
  • Aizoon <small>L.</small>
  • Gunniopsis <small>Pax</small>
  • Tetragonia <small>L.</small>

Subfamily Mesembryanthemoideae

Genera:

  • Aptenia <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Aridaria <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Aspazoma <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Brownanthus <small>Schwantes</small>, synonym of Mesembryanthemum
  • Dactylopsis <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Mesembryanthemum <small>L.</small>
  • Phyllobolus <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Prenia <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Psilocaulon <small>N.E.Br</small>, synonym of Mesembryanthemum
  • Synaptophyllum <small>N.E.Br</small>, synonym of Mesembryanthemum

Subfamily Ruschioideae

Genera:

{|

|- valign=top

|

;Tribe Apatesieae

  • Apatesia <small>N.E.Br</small>
  • Carpanthea <small>N.E.Br</small>
  • Caryotophora <small>Leistner</small>, synonym of Skiatophytum
  • Conicosia <small>N.E.Br</small>
  • Hymenogyne <small>Haw.</small>
  • Saphesia <small>N.E.Br</small>
  • Skiatophytum <small>L.Bolus</small>

|

;Tribe Dorotheantheae

  • Aethephyllum <small>N.E.Br</small>, synonym of Cleretum
  • Cleretum <small>N.E.Br</small>
  • Dorotheanthus <small>Schwantes</small>, synonym of Cleretum

|}

;Tribe Ruschieae

  • Acrodon <small>N.E.Br</small>
  • Aloinopsis <small>Schwantes</small>
  • Amphibolia <small>L.Bolus ex A.G.J.Herre</small>
  • Antegibbaeum <small>Schwantes ex C.Weber</small>
  • Antimima <small>N.E.Br</small>
  • Arenifera <small>Herre</small>, synonym of Mesembryanthemum
  • Argyroderma <small>N.E.Br</small>
  • Astridia <small>Dinter</small>
  • Bergeranthus <small>Schwantes</small>
  • Bijlia <small>N.E.Br</small>, synonym of Pleiospilos
  • Braunsia <small>Schwantes</small>
  • Brianhuntleya <small>Chess. et al.</small>
  • Carpobrotus <small>N.E.Br</small>
  • × Carruanthophyllum (Carruanthus × Machairophyllum)
  • Carruanthus <small>(Schwantes) Schwantes</small>
  • Cephalophyllum <small>N.E.Br</small>
  • Cerochlamys <small>N.E.Br</small>
  • Chasmatophyllum <small>Dinter & Schwantes</small>
  • Cheiridopsis <small>N.E.Br</small>
  • Circandra <small>N.E.Br</small>, synonym of Erepsia
  • Conophytum <small>N.E.Br</small>
  • Corpuscularia <small>Schwantes</small>, synonym of Delosperma
  • Cylindrophyllum <small>Schwantes</small>
  • Delosperma <small>N.E.Br</small>
  • Dicrocaulon <small>N.E.Br</small>
  • Didymaotus <small>N.E.Br</small>
  • Dinteranthus <small>Schwantes</small>
  • Diplosoma <small>Schwantes</small>
  • Disphyma <small>N.E.Br</small>
  • Dracophilus <small>(Schwantes) Dinter & Schwantes</small>
  • Drosanthemum <small>Schwantes</small>
  • Eberlanzia <small>Schwantes</small>
  • Ebracteola <small>Dinter & Schwantes</small>
  • Ectotropis <small>N.E.Br</small>, synonym of Delosperma
  • Enarganthe <small>N.E.Br</small>
  • Erepsia <small>N.E.Br</small>
  • Esterhuysenia <small>L.Bolus</small>, synonym of Lampranthus
  • Faucaria <small>Schwantes</small>
  • Fenestraria <small>N.E.Br</small>
  • Frithia <small>N.E.Br</small>
  • Gibbaeum <small>Haw. ex N.E.Br</small>
  • Glottiphyllum <small>Haw. ex N.E.Br</small>
  • Hallianthus <small>H.E.K.Hartmann</small>
  • Hereroa <small>(Schwantes) Dinter & Schwantes</small>
  • Ihlenfeldtia <small>H.E.K.Hartmann</small>, synonym of Cheiridopsis
  • Imitaria <small>N.E.Br</small>, synonym of Gibbaeum
  • Jacobsenia <small>L.Bolus & Schwantes</small>
  • Jensenobotrya <small>A.G.J.Herre</small>
  • Jordaaniella <small>H.E.K.Hartmann</small>
  • Juttadinteria <small>Schwantes</small>
  • Khadia <small>N.E.Br</small>
  • Lampranthus <small>N.E.Br</small>
  • Lapidaria <small>(Dinter & Schwantes) N.E.Br.</small>
  • Leipoldtia <small>L.Bolus</small>
  • Lemonanthemum <small>Klak</small>
  • Lithops <small>N.E.Br</small>
  • Machairophyllum <small>Schwantes</small>
  • Malephora <small>N.E.Br</small>
  • Malephoropsis
  • Malotigena <small>Niederle</small>
  • Marlothistella <small>Schwantes</small>
  • Mestoklema <small>N.E.Br. ex Glen</small>
  • Meyerophytum <small>Schwantes</small>
  • Mitrophyllum <small>Schwantes</small>
  • Monilaria <small>(Schwantes) Schwantes</small>
  • Mossia <small>N.E.Br</small>
  • Muiria <small>N.E.Br</small>
  • Namaquanthus <small>L.Bolus</small>
  • Namibia <small>(Schwantes) Schwantes</small>
  • Nananthus <small>N.E.Br</small>
  • Nelia <small>Schwantes</small>
  • Neohenricia <small>L.Bolus</small>
  • Octopoma <small>N.E.Br</small>
  • Odontophorus <small>N.E.Br</small>, synonym of Cheiridopsis
  • Oophytum <small>N.E.Br</small>
  • Orthopterum <small>L.Bolus</small>
  • Oscularia <small>Schwantes</small>
  • Ottosonderia <small>L.Bolus</small>
  • Phiambolia <small>Klak</small>
  • Pleiospilos <small>N.E.Br</small>
  • Polymita <small>N.E.Br</small>, synonym of Schlechteranthus
  • Psammophora <small>Dinter & Schwantes</small>
  • Rabiea <small>N.E.Br</small>
  • Rhinephyllum <small>N.E.Br</small>
  • Rhombophyllum <small>(Schwantes) Schwantes</small>
  • Roosia <small>van Jaarsv.</small>, synonym of Lampranthus
  • Ruschia <small>Schwantes</small>
  • Ruschianthemum <small>Friedrich</small>, synonym of Stoeberia
  • Ruschianthus <small>L.Bolus</small>
  • Sarcozona <small>J.M.Black</small>
  • Schlechteranthus <small>Schwantes</small>
  • Schwantesia <small>Dinter</small>
  • Scopelogena <small>L.Bolus</small>
  • Sederbergia

;Tribe Anisostigmateae

  • Anisostigma <small>Schinz</small>
  • Tribulocarpus <small>S.Moore</small>

;Tribe Sesuvieae

  • Sesuvium <small>L.</small>
  • Trianthema <small>L.</small>
  • Zaleya <small>Burm.f.</small>

Unplaced genera

Include;

  • Hammeria
  • Peersia

Uses

thumb|right|Tetragonia tetragonoides ("New Zealand spinach")

Several genera are cultivated. Lithops, or "living stones", are popular as novelty house plants because of their stone-like appearance.

Some species are edible, including:

  • Carpobrotus edulis (Hottentot fig, highway ice plant) has edible leaves and fruit.
  • Mesembryanthemum crystallinum has edible leaves.

C. edulis was introduced to California in the early 1900s to stabilize soil along railroad tracks and has become invasive. In southern California, ice plants are sometimes used as firewalls; however, they do burn if not carefully maintained.

References

Further reading

  • Aizoaceae in L. Watson and M.J. Dallwitz (1992 onwards). The families of flowering plants
  • NCBI Taxonomy Browser
  • P. Chesselet (2004 onwards). Interactive Mesembs2
  • Plants of southern Africa (2005 onwards). SANBI
  • Aizoaceae of South Africa
  • Family Aizoaceae Flowers in Israel
  • Aizoaceae in BoDD – Botanical Dermatology Database