Iridaceae

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Iridaceae Temporal range: 60–0  Ma PreꞒ Ꞓ O S D C P T J K Pg N Middle Paleocene - Recent
Crocus vernus
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Asparagales
Family:	Iridaceae Juss.[1]
Subfamilies and tribes
Subfamily Aristeoideae Subfamily Crocoideae Tribe Tritoniopsideae Tribe Watsonieae Tribe Gladioleae Tribe Freesieae Tribe Ixieae Subfamily Geosiridoideae Subfamily Iridoideae Tribe Diplarreneae Tribe Irideae Tribe Sisyrinchieae Tribe Tigridieae Tribe Trimezieae Subfamily Isophysidoideae Subfamily Nivenioideae Subfamily Patersonioideae

Iridaceae (/ɪrɪˈdeɪsiˌaɪ, -siːˌiː/) is a family of plants in order Asparagales, taking its name from the irises. It has a nearly global distribution, with 69 accepted genera with a total of c. 2500 species.^[2][3][4] It includes a number of economically important cultivated plants, such as species of Freesia, Gladiolus, and Crocus, as well as the crop saffron.

Members of this family are

The family name comes from the genus Iris, the family's largest and best-known genus in Europe. This genus dates from 1753, when it was coined by Swedish botanist, Carl Linnaeus. Its name derives from the Greek goddess, Iris, who carried messages from Olympus to earth along a rainbow, whose colors were seen by Linnaeus in the multi-hued petals of many of the species.

Taxonomy

Iridaceae is currently recognized as nested in the

Subfamily Nivenioideae contained six genera from South Africa, Australia and Madagascar, including the core genera and only true shrubs in the family (Klattia, Nivenia and Witsenia).^[7] Upon phylogenetic analysis, subfamily Crocoideae is always found nested within Nivenioideae, leading to it not being a monophyletic taxon.^[5] A revised description of these groups led to the description of Aristea, Geosiris, and Patersonia each as separate subfamilies, retaining a core, monophyletic Nivenioideae.^[5] It is now distinguished as being evergreen shrubs with monocot-type secondary thickening, shield shaped seeds, and paired rhipidia with only one to two flowers in each cluster.^[5]

Iridoideae

Subfamily

Members of the subfamilies Crocoideae and Nivenioideae first began cladogenesis in arid conditions in Africa, accelerating for Crocoideae as the Mediterranean climate emerged in Southern Africa.^[5] A similar process occurred for the tribe Tigridieae in Iridoideae following long-distance dispersal from South to North America, resulting in high levels of endemism.^[18][5] In the tribe Sisyrichieae, the continued formation of the Andes supported the movement to lower elevations along the Atlantic.^[19]

The aerial portions of deciduous species die back when the bulb or corm enters dormancy. The plants thus survive periods that are unfavorable for growth by retreating underground. This is particularly useful in grasslands and fynbos, which are adapted to regular burning in the dry season. At this time the plants are dormant and their bulbs or corms are able to survive the heat of the fires underground. Veld fires clear the soil surface of competing vegetation, as well as fertilize it with ash. With the arrival of the first rains, the dormant corms are ready to burst into growth, sending up flowers and stems before they can be shaded out by other vegetation. Many grassland and fynbos irids flower best after fires and some fynbos species will only flower in the season after a fire.

The majority of Iridaceae are

69 genera have been recognized in the family, with a total of 2597 species described.[3] The Afrotropical realm, and in particular South Africa, have the greatest diversity of genera.^[25]