1.2- Scientific Classification of the Subfamily Agapanthoideae The genus Agapanthus was established by L'Heritier in 1788. In the Cronquist system, the genus was placed in a very broadly defined family Liliaceae, along with other lilioid monocots. In 1985, Dahlgren, Clifford, and Yeo placed Agapanthus in Alliaceae, close to Tulbaghia. Their version of Alliaceae also included several genera that would later be transferred to Themidaceae. In 1996, following a phylogenetic analysis of DNA sequences of the generbcL, Themidaceae was resurrected and Agapanthus was removed from Alliaceae. The authors found Agapanthus to be sister to Amaryllidaceae and transferred it to that family. This was not accepted by the Angiosperm Phylogeny Group (APG) when they published the original APG system in 1998, because the clade consisting of Agapanthus and Amaryllidaceae had only 63% bootstrap support. The APG system recognized three separate families, Agapanthaceae, Alliaceae sensu stricto, and Amaryllidaceae sensu stricto. Agapanthaceae consisted of Agapanthus only, and Dahlgren's idea that it is close to Tulbaghia was rejected. When the APG II system was published in 2003, it offered the option of combining Agapanthaceae, Alliaceae sensu stricto, and Amaryllidaceae sensu stricto to form a larger family, Alliaceae sensu lato. When the name Amaryllidaceae was conserved by the ICBN for this larger family, its name was changed from Alliaceae to Amaryllidaceae, but its circumscription remained the same. When APG II was replaced by APG III in 2009, Agapanthaceae was no longer accepted, but was treated as subfamily Agapanthoideae of the larger version of Amaryllidaceae. Further molecular phylogenetic analyses of DNA sequences have confirmed that Agapanthus is sister to a clade consisting of subfamilies Allioideae and Amaryllidoideae of the family Amaryllidaceae (sensu APG III). The Subfamily Agapanthoideae consists of a single genus, Agapanthus, and is endemic to South Africa.
2- The Genus Agapanthus
2.1- Overview Agapanthusis the only genus in the subfamily Agapanthoideae of the flowering plant familyAmaryllidaceae. The family is in the monocot orderAsparagales. The name is derived from scientific Greek: αγάπη (agape) = love, άνθος (anthos) = flower. Some species of Agapanthus are commonly known as lily of the Nile (or African lily in the UK), although they are not lilies and all of the species are native to Southern Africa (South Africa, Lesotho, Swaziland, Mozambique) though some have become naturalized in scattered places around the world (Australia, Great Britain, Mexico, Ethiopia, Jamaica, etc.). Species boundaries are not clear in the genus, and in spite of having been intensively studied, the number of species recognized by different authorities varies from 6 to 10. The type species for the genus is Agapanthus africanus. A great many hybrids and cultivars have been produced and they are cultivated throughout warm areas of the world, and can especially be spotted all throughout Northern California. Most of these were described in a book published in 2004. 2.2- Description Agapanthus is a genus of herbaceousperennials that mostly bloom in summer. The leaves are basal and curved, linear, and up to 60 cm (24 in) long. They are arranged in two rows. The inflorescence is a pseudo-umbel subtended by two large bracts at the apex of a long, erect scape, up to 2 m (6.6 ft) tall. They have funnel-shaped flowers, in hues of blue to purple, shading to white. Some hybrids and cultivars have colors not found in wild plants. The ovary is superior. The style is hollow. Agapanthus does not have the distinctive chemistry of Alliaceae. 2.3- Species As of December 2013, the World Checklist of Selected Plant Families recognises seven species: 1- Agapanthus africanus (L.) Hoffmanns (syn. A. umbellatus; African Lily or African Tulip) 2- Agapanthus campanulatus F.M.Leight. (African bluebell, African Blue lily or Bell Agapanthus) 3- Agapanthus caulescens Spreng. 4- Agapanthus coddii F.M.Leight. (Codd's Agapanthus or Blue Lily) 5- Agapanthus inapertus Beauverd (including A. dyeri; Drakensberg Agapanthus or Drooping Agapanthus) 6- Agapanthus praecox Willd. (including A. comptonii, A. orientalis; Common Agapanthus, Blue Lily, African Lily, or Lily of the Nile) 7- Agapanthus walshii L.Bolus