Asphodeloideae

The Asphodeloideae are distinguished by a general presence of anthraquinones, simultaneous microsporogenesis, atypical ovules morphology, and the presence of an aril. Asphodeloideae also have a characteristic secondary growth by means of a secondary thickening meristem. The aloin cells are said to produce the characteristic thick exudate that is produced when the succulent leaf of aloe is severed. The aloin cells produce anthraquinone and chromone derivatives, which may be responsible for the medicinal attributes of Aloe. == Taxonomy ==

Lotsy (1911) placed a number of genera (Kniphofia, Notosceptrum, Chortolirion and Aloe) into a family, separate from Asphodelaceae, the Aloinaceae. Other taxonomists have subsequently circumscribed a tribe, Aloineae (or Aloeae) to include Gasteria, Haworthia and Aloe. Other taxonomic terms have included Aloaceae, Alooideae, Aloideae, Aloidea, Aloides, Aloinae and Aloeace, with the type genus Aloe. Phylogeny of Asphodeloideae There is agreement among many researchers that Asphodeloideae can be further divided into a monophyletic group comprising Aloe and its immediate relatives, and a nonmonophyletic group of the remaining genera. The monophyletic group can be treated as the tribe Aloeae within the subfamily Asphodeloideae by those adopting the broad APG IV system circumscription of the Asphodelaceae. (Alternatively, it may be treated as the subfamily Alooideae within a more narrowly circumscribed family Asphodelaceae.) The genera within Alooideae have several morphological characters that can be distinguished in the field, namely the arrangement and type of leaf and inflorescence. Evidence for monophyly of Aloeae is based on distinctive karyotype and characteristic leaf morphology. The Bulbine group has characteristics of Aloeae, but is not included in the group due to a lack of tubular flowers. Kniphofia is considered an outgroup of Aloeae since it has tubular flowers and a fusion of perianth segments, but it lacks succulent leaves. == Selected list of genera ==

The genera listed below are those accepted by APWeb . Other treatments combine some of these genera into as few as seven. • Aloe L. • Aloiampelos Klopper & Gideon F.Sm. • Aloidendron (A.Berger) Klopper & Gideon F.Sm. • Aristaloe Boatwr. & Manning • Astroloba Uitewaal • Asphodeline Rchb. • Asphodelus L. • Bulbine Wolf • Bulbinella Kunth • Chortolirion A.Berger • Eremurus M.Bieb. • Gasteria Duval • Gonialoe (Baker) Boatwr. & J.C.Manning • Haworthia Duval • Haworthiopsis G.D.Rowley • Jodrellia Baijnath • Kniphofia Moench • Kumara Medik • Trachyandra Kunth • Tulista Raf. For a phylogeny of the family, see the phylogenetic tree at Asphodelaceae. ==References==