Allium dregeanum | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Asparagales |
Family: | Amaryllidaceae |
Subfamily: | Allioideae |
Genus: | Allium |
Species: | A. dregeanum |
Binomial name | |
Allium dregeanum Kunth | |
Allium dregeanum is the sole known species of Allium endemic to sub-Saharan Africa. [1] It has also been described as the only Allium species endemic to the Southern Hemisphere, [2] [3] though some descriptions of the genus also include Allium juncifolium (Chile) and Allium sellovianum (Brazil), [4] [5] which are much less studied than Allium dregeanum. The distribution of Allium dregeanum extends from the summer-rainfall region, into the winter-rainfall zone of South Africa. [6] Since Allium species are almost exclusively found in the Northern Hemisphere, with major centers of diversity in Central Asia and western North America, [2] the biogeographical history of Allium dregeanum is of interest.
Though some theories have been put forward, no explanation for the geographic isolation of Allium dregeanum has been confirmed. In 1976, De Wilde-Dufyes proposed that Allium dregeanum is a modification of the European species Allium ampeloprasum, and may have been brought to South Africa by early European settlers. [6] De Saarker et al. contradicted this theory in 1997, when they explored genetic similarities between Allium dregeanum and Allium ampeloprasum, and did not find evidence of a significant genetic relationship. They also point to evidence that Allium dregeanum was already established in South Africa in the mid-17th century, when the first Dutch settlers colonized South Africa, but do not suggest other explanations for Allium dregeanum's isolation. [1]
Allium dregeanum occurs at elevations of 100-1000m, and flowers in spring and early summer (October to December). [6] It can grow to 0.6m by 0.2m, growing best in well-drained soils in sunny areas. [7] Allium dregeanum is also notable for its high chromosome counts: polyploidy is not uncommon in Allium, with 14% of representative Allium species exhibiting more than two sets of chromosomes, [8] but Allium dregeanum has particularly high ploidy levels, and can be octoploid or decaploid. [1]
Asparagales is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group (APG) and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in the monocots amongst the lilioid monocots. The order has only recently been recognized in classification systems. It was first put forward by Huber in 1977 and later taken up in the Dahlgren system of 1985 and then the APG in 1998, 2003 and 2009. Before this, many of its families were assigned to the old order Liliales, a very large order containing almost all monocots with colorful tepals and lacking starch in their endosperm. DNA sequence analysis indicated that many of the taxa previously included in Liliales should actually be redistributed over three orders, Liliales, Asparagales, and Dioscoreales. The boundaries of the Asparagales and of its families have undergone a series of changes in recent years; future research may lead to further changes and ultimately greater stability. In the APG circumscription, Asparagales is the largest order of monocots with 14 families, 1,122 genera, and about 36,000 species.
The flowering plant genus Ipheion belongs to Allioideae, a subfamily of the family Amaryllidaceae. The World Checklist of Selected Plant Families no longer recognize the genus, regarding it as a synonym of Tristagma, although The Plant List accepts two species.
Allium tuberosum is a species of plant native to the Chinese province of Shanxi, and cultivated and naturalized elsewhere in Asia and around the world.
Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species, that including a number of species of aquatic plant, for instance the tape-grasses, the well known Canadian waterweed, and frogbit.
Crocoideae is one of the major subfamilies in the family Iridaceae.
The tribe Griffineae includes 2 genera with 22 species from South America which are actually endemic to Brazil. A typical character of the representatives of the tribe are the flowers - They are with blue or lilac color collected into an umbel. Only the members of this tribe and the genus Lycoris are able to form flowers with such color in the whole family Amaryllidaceae. The plants in this group are typical perennial flowers which are producing bulbs. The leaves are green, with elliptical form in the most of the cases but in some members as in Worsleya they are sword-shaped.
Alan W. Meerow is an American botanist, born in New York City in 1952. He specializes in the taxonomy of the family Amaryllidaceae and the horticulture of palms and tropical ornamental plants. He also works on the population genetics and molecular systematics of cycads and palms.
Allium siculum, known as honey garlic, Sicilian honey lily, Sicilian honey garlic, or Mediterranean bells, is a European and Turkish species of plants genus Allium. It is native to the regions around the Mediterranean and Black Seas, and grown in other regions as an ornamental and as a culinary herb.
Narcisseae is a small tribe of plants belonging to the subfamily Amaryllidoideae of the Amaryllis family (Amaryllidaceae), where it forms part of the Eurasian clade, and is one of three tribes in the European (Mediterranean) clade. It contains two genera and approximately 58 species, but probably also Lapiedra. The two genera are distinguished from each other by the presence of a paraperigonium in the former.
Galantheae is a tribe of plants belonging to the subfamily Amaryllidoideae of the Amaryllis family (Amaryllidaceae). As of 2017, it contains three genera, although more were included previously. The position of the ovary is inferior.
Gilliesieae is a tribe of herbaceous geophyte plants belonging to the subfamily Allioideae of the Amaryllis family (Amaryllidaceae). Described in 1826, it contains fifteen genera and about eighty species. It has been variously treated as a subfamily or tribe. It is native to the Southern United States, Central and South America, predominantly Chile. Of the three tribes of genera that make up the subfamily Allioideae, Gilliesieae is the largest and most variable. The tribe was divided into two tribes in 2014, Gilliesiae s.s. and Leucocoryneae, based on differences in floral symmetry and septal nectaries.
Nina Rønsted is a Danish botanist, who is Director of Science and Conservation at The National Tropical Botanical Garden, Hawaii.
Allioideae is a subfamily of monocot flowering plants in the family Amaryllidaceae, order Asparagales. It was formerly treated as a separate family, Alliaceae. The subfamily name is derived from the generic name of the type genus, Allium. It is composed of about 18 genera.
Allium is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. The generic name Allium is the Latin word for garlic, and the type species for the genus is Allium sativum which means "cultivated garlic".
Pancratieae are a small European tribe of subfamily Amaryllidoideae, consisting of two genera including the type genus, Pancratium.
Hymenocallideae is a tribe, where it forms part of the Andean clade, one of two American clades. The tribe was originally recognised by both Meerow (1995) and the Muller-Doblies' (1996). Its phylogenetic position within the Amaryllidoideae was established by Meerow et al. in 2000, while in-depth infratribal relationships were established in 2002.
Cliviinae is a small subtribe of Haemantheae, and therefore within the African clades of Amaryllidoideae. It consists of two genera, Clivia, and Cryptostephanus.
Haemanthinae is a small subtribe of Haemantheae, and therefore within the African clades of Amaryllidoideae. It consists of two genera, Haemanthus, and Scadoxus.
Gethyllidinae is a small subtribe within the amaryllis family. It is within tribe Haemantheae, and therefore within the African clades of Amaryllidoideae. It contains two genera, Gethyllis and Apodolirion, both are endemic to southern Africa.
The precise taxonomy of the genus Allium is still poorly understood with incorrect descriptions being widespread. With over 850 species distributed over the Northern hemisphere Allium is the sole genus in the Allieae, one of four tribes of subfamily Allioideae (Amaryllidaceae). New species continue to be described and Allium is both highly variable and one of the largest monocotyledonous genera, but the precise taxonomy of Allium is poorly understood, with incorrect descriptions being widespread. The difficulties arise from the fact that the genus displays considerable polymorphism and has adapted to a wide variety of habitats. Furthermore, traditional classications had been based on homoplasious characteristics. However, the genus has been shown to be monophyletic, containing three major clades, although some proposed subgenera are not. Some progress is being made using molecular phylogenetic methods, and the internal transcribed spacer (ITS) region, including the 5.8S rDNA and the two spacers ITS1 and ITS2, is one of the more commonly used markers in the study of the differentiation of the Allium species.