Agapanthus is a genus now considered to be in the Agapanthaceae family. It was previously considered to be in the Alliaceae family but it does not have the onion or garlic smell, and DNA sequencing indicates a closer relationship to Amaryllidaceae.
Plants grow from rhizomes and have strap-like leaves. Flowers are umbels of blue or white funnel-shaped or tubular flowers. This genus is found in rocky grasslands on the southern and eastern fringes of southern Africa. Species in areas where there is year round rainfall are evergreen and those where rainfall is sparse in winter are deciduous. Information from the South African National Biodiversity Institute's web pages tells about this genus with more information too about Agapanthus praecox.
Seeds are somewhat ephemeral and will last for about 6 months.
Molecular Biology and Genetics
Statistics of barcoding coverage
Specimens with Sequences:19
Specimens with Barcodes:17
Species With Barcodes:4
|It has been suggested that this article or section be merged with Agapanthaceae. (Discuss)|
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.  Most of these were described in a book published in 2004. 
Zonneveld & Duncan (2003) divided Agapanthus into six species (A. africanus, A. campanulatus, A. caulescens, A. coddii, A. inapertus, A. praecox).  Four additional taxa were recognised by Leighton (1965) as species (A. comptonii, A. dyeri, A. nutans, A. walshii),  but were given subspecific rank by Zonneveld & Duncan. All species recognized by Leighton or by Zonneveld and Duncan are listed below. A. orientalis is also listed.
- Agapanthus africanus (syn. A. umbellatus; African Lily or African Tulip)
- Agapanthus campanulatus (African bluebell, African Blue lily or Bell Agapanthus)
- Agapanthus caulescens
- Agapanthus coddii (Codd's Agapanthus or Blue Lily)
- Agapanthus comptonii
- Agapanthus dyeri
- Agapanthus inapertus (Drakensberg Agapanthus or Drooping Agapanthus)
- Agapanthus nutans
- Agapanthus orientalis
- Agapanthus praecox (Common Agapanthus, Blue Lily, African Lily, or Lily of the Nile)
- Agapanthus walshii
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.
In 1985, Dahlgren, Clifford, and Yeo placed Agapanthus in Alliaceae, close to Tulbaghia.  Their version of Alliaceae differed from any that are recognized today in that it included Agapanthus and in that it included several genera that would later be transferred to Themidaceae.
In 1996, in a phylogenetic analysis of DNA sequences of the gene rbcL, 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 when they published the APG system in 1998, because the clade consisting of Agapanthus and Amaryllidaceae had only 63% bootstrap support. The APG system recognized the families Agapanthaceae, Alliaceae, and Amaryllidaceae. Agapanthaceae consisted of Agapanthus only, and Dahlgren's idea that it is close to Tulbaghia was rejected. The APG circumscriptions of the latter two families would eventually become known as Alliaceae sensu stricto, and Amaryllidaceae sensu stricto.
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.  Also in 2009, Armen Takhtajan recognized the three smaller families allowed by APG II, instead of combining them as in APG III. 
Molecular phylogenetic analysis of DNA sequences has shown that Agapanthus is sister to a clade consisting of subfamilies Allioideae and Amaryllidoideae of the family Amaryllidaceae (sensu APG III).  These two subfamilies are equivalent to the families Alliaceae sensu stricto, and Amaryllidaceae sensu stricto, respectively.
Cultivation and uses
Agapanthus africanus can be grown within USDA plant hardiness zones 9 to 11. In lower-numbered zones, the bulbs should be placed deeper in the soil and mulched well in the fall. Agapanthus can be propagated by dividing the bulbs or by seeds. The seeds of most varieties are fertile.
- ^ Sunset Western Garden Book, 1995:606–607
- ^ Stevens, P.F. (2001 onwards), Angiosperm Phylogeny Website: Asparagales: Agapanthoideae, http://www.mobot.org/mobot/research/apweb/orders/asparagalesweb.htm#Agapanthaceae
- ^ Klaus Kubitzki. 1998. "" pages 58-60. In: Klaus Kubitzki (editor). 1998. The Families and Genera of Vascular Plants volume III. Springer-Verlag: Berlin;Heidelberg, Germany. ISBN 978-3-540-64060-8
- ^ "Agapanthus" In: Index Nominum Genericorum. In: Regnum Vegetabile (see External links below).
- ^ Anthony Huxley, Mark Griffiths, and Margot Levy (1992). The New Royal Horticultural Society Dictionary of Gardening. The Macmillan Press,Limited: London. The Stockton Press: New York. ISBN 978-0-333-47494-5 (set).
- ^ Wim Snoeijer. 2004. Agapanthus A revision of the genus. Timber Press: Portland, OR, USA. ISBN 978-0-88192-631-6.
- ^ Zonneveld, B. J. M. & Duncan, G. D. (2003). "Taxonomic implications of genome size and pollen colour and vitality for species of Agapanthus L'Heritier (Agapanthaceae)". Plant Systematics and Evolution. 241: 115-123.
- ^ Leighton, F. M. (1965). "The Genus Agapanthus L'Heritier". Journal of South African Botany, supplementary volume IV.
- ^ James L. Reveal. undated. "Agapanthus" At: Alphabetical Listing by Genera of Validly Published Suprageneric Names At: Home page of James L. Reveal and C. Rose Broome.
- ^ Rolf M.T. Dahlgren, H. Trevor Clifford, and Peter F. Yeo. 1985. The Families of the Monocotyledons. Springer-Verlag: Berlin, Heidelberg, New York, Tokyo. ISBN 978-3-540-13655-2. ISBN 978-0-387-13655-4.
- ^ Michael F. Fay and Mark W. Chase. 1996. "Resurrection of Themidaceae for the Brodiaea alliance, and recircumscription of Alliaceae, Amaryllidaceae, and Agapanthoideae". Taxon 45(3):441-451. (see External links below).
- ^ Mark W. Chase, James L. Reveal, and Michael F. Fay. "A subfamilial classification for the expanded asparagalean families Amaryllidaceae, Asparagaceae and Xanthorrhoeaceae". Botanical Journal of the Linnean Society 161(2):132–136.
- ^ Armen L. Takhtajan (Takhtadzhian). Flowering Plants second edition (2009). Springer Science+Business Media. ISBN 978-1-4020-9608-2.
- ^ J. Chris Pires, Ivan J. Maureira, Thomas J. Givnish, Kenneth J. Sytsma, Ole Seberg, Gitte Petersen, Jerrold I. Davis, Dennis W. Stevenson, Paula J. Rudall, Michael F. Fay, and Mark W. Chase. 2006. "Phylogeny, genome size, and chromosome evolution of Asparagales". Aliso 22(Monocots: Comparative Biology and Evolution):287-304. ISSN 0065-6275.
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