| Mesembryanthemum | |
|---|---|
| |
| Mesembryanthemum nodiflorum | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Aizoaceae |
| Subfamily: | Mesembryanthemoideae |
| Genus: | Mesembryanthemum L. |
| Species | |
|
See text for accepted species | |
| Synonyms[1] | |
| |
Mesembryanthemum is a genus of flowering plants in the family Aizoaceae, indigenous to southern Africa. As with many members of that family, it is characterized by long-lasting flower heads. Flowers of Mesembryanthemum protect their gametes from night-time dews or frosts but open in sunlight.[citation needed] There is an obvious evolutionary advantage to doing this; where sun, dew, frost, wind or predators are likely to damage exposed reproductive organs, closing may be advantageous during times when flowers are unlikely to attract pollinators.[citation needed]
Many Mesembryanthemum species are known as ice plants because of the glistening globular bladder cells covering their stems, fruit and leaves,[2] "... they sparkle like ice crystals".[3] In South Africa, Mesembryanthemums are known as "vygies" (from Afrikaans "vy"), although that term refers to many plants in the family Aizoaceae.
Species formerly placed in Mesembryanthemum have been transferred to other genera, such as Cleretum and Carpobrotus, although sources differ.
Jacob Breyne coined the name of the flower in 1684, using the spelling Mesembrianthemum ("midday flower"[4]), from the Greek roots μεσημβρία, meaning "noon", and ἄνθεμον, meaning "flower", because the species known in his time flowered at midday. In 1719, with the discovery that some species flowered at night, Johann Jacob Dillenius changed the spelling to Mesembryanthemum ("flower with the pistil in the center"[4]), rederiving the first part of the word from Greek μεσος ("middle") and ἔμβρυον ("pistil" or "embryo"). Carl Linnaeus used the Dillenius spelling (with the "y") in his description of the Mesembryanthemum species and the International Code of Botanical Nomenclature requires the retention of the original, deliberate spelling.[4][5]
Mesembryanthemums are often cultivated as ornamental plants for their showy flowers. Ornamental plants may escape into the wild and consequently have become widely naturalized outside their native range. They are considered an invasive weed in certain places.[citation needed]
Some Mesembryanthemum species are thought to be hallucinogenic plants, like related Aizoaceae,[6] and as such may be subject to legal restrictions (e.g., Louisiana State Act 159).
As of March 2019[update], Plants of the World Online accepted the following 108 species:[1]
Except for ornamental purposes, growing, selling or possessing any species of Mesembryanthemum is prohibited by Louisiana State Act 159.
