Themidaceae

Brodiaeoideae are a monocot subfamily of flowering plants in the family Asparagaceae, order Asparagales. They have been treated as a separate family, Themidaceae. They are native to Central America and western North America, from British Columbia to Guatemala.Ole Seberg. 2007. "Themidaceae" page 404. In: Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: Ontario, Canada. The name of the subfamily is based on the type genus '' Brodiaea''.

In molecular phylogenetic analyses, Brodiaeoideae is strongly supported as monophyletic. It is probably sister to Scilloideae.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. Recent treatments have divided Brodiaeoideae (or Themidaceae) into 12 genera.Knud Rahn. 1998. "Themidaceae" pages 436-441. In: Klaus Kubitzki (general editor) with Klaus Kubitzki, Herbert F.J. Huber, Paula J. Rudall, Peter F. Stevens, and Thomas Stützel (volume editors). ''The Families and Genera of Vascular Plants'' volume III. Springer-Verlag: Berlin;Heidelberg, Germany. The monophyly of several of the genera remains in doubt. As currently circumscribed, the largest genera are ''Triteleia'', with 15 species, and ''Brodiaea'', with 14.Flora of North America Editorial Committee. 2002. ''Flora of North America'' volume 26:321-347. Oxford University Press. . see ''External links'' below. Nine of the 12 genera are known in cultivation, but only species of ''Brodiaea'' and ''Triteleia'' are commonly grown. 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. (set).

Description

The following description is derived from two sources.Armen L. Takhtajan (Takhtadzhian). ''Flowering Plants'' second edition (2009). Springer Science+Business Media. .

Perennial herbs arising from a starchy corm; a new corm arising each year from the old one.

Leaves linear, often fleshy, forming a closed sheath at their base. Veins parallel.

Inflorescence an umbel, or rarely a single flower, at the apex of a solitary scape. Flowers bisexual, actinomorphic. Tepals all similar, in 2 whorls of 3.

Fertile stamens 6, or 3 and alternating with 3 staminodes. Stamens and staminodes inserted on tepals. Anthers basifixed and introrse.

Ovary superior and trilocular.

Fruit a loculicidal capsule. Seed covered with phytomelan.

History

For most of the 19th and 20th centuries, when the group was recognized at all, it was usually at tribal rank and usually called Brodiaeeae. Most authors assigned it to Liliaceae, Alliaceae, or Amaryllidaceae. In 1985, Dahlgren, Clifford, and Yeo treated it as tribe Brodiaeeae of Alliaceae.Rolf M.T. Dahlgren, H. Trevor Clifford, and Peter F. Yeo. 1985. ''The Families of the Monocotyledons''. Springer-Verlag: Berlin, Heidelberg, New York, Tokyo. . .

Toward the end of the 20th century, it became increasingly evident that the heterogeneous Liliaceae recognized by most authors was several times polyphyletic and that ''Brodiaea'' and its relatives were closer to Asparagus than to '' Allium'' or '' Amaryllis''. For these reasons, the family Themidaceae was resurrected in an article in Taxon in 1996.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). The name 'Themidaceae' was first used by Richard Salisbury in 1866.Richard Salisbury. 1866. ''The Genera of Plants. A Fragment Containing Part of Liriogamae'':84. John van Voorst: Paternoster Row, London, England. (see ''External links'' below). The name was based on the now-defunct genus ''Themis'', which was established by Salisbury along with the family. The only species ever assigned to ''Themis'' was ''Themis ixioides''. Its name was changed to ''Brodiaea ixioides'' by Sereno Watson in 1879,Sereno Watson. 1879. "Revision of the North American Liliaceae". In: ''Proceedings of the American Academy of Arts and Sciences'' 14:238. (see ''External links'' below). then to ''Triteleia ixioides'' by Edward Lee Greene in 1886.Edward Lee Greene. 1886. "Some Genera Which have been Confused Under the Name ''Brodiaea''". In: ''Bulletin of the California Academy of Sciences'' 2(6):142. (see ''External links'' below). It is known as ''Triteleia ixioides'' in Flora of North America.

When the Angiosperm Phylogeny Group published the APG II system in 2003, Themidaceae was treated as an optional circumscription for those who thought that Asparagaceae sensu lato should be divided into smaller segregate families. When the APG III system was published in 2009, Themidaceae was not accepted. In an accompanying article, it was treated as Brodiaeoideae, one of 7 subfamilies in Asparagaceae.

Genera

According to the Angiosperm Phylogeny Website , the genera included in the subfamily are:

*''Androstephium'' Torr.
*'' Bessera'' Schult.f. (including ''Behria'')
*''Bloomeria'' Kellogg
*'' Brodiaea'' Sm.
*''Dandya'' H.E.Moore
*''Dichelostemma'' Kunth (including ''Brevoortia'', ''Dipterostemon'', ''Stropholirion'')
*'' Milla'' Cav. (including ''Diphalangium'')
*'' Muilla'' S.Watson ex Benth.
*''Petronymphe'' H.E.Moore
*'' Triteleia'' Douglas ex Lindl. (including ''Hesperoscordium'', ''Themis'')
*''Triteleiopsis'' Hoover

References

Bibliography

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External links

Brodiaeoideae
At

At
Missouri Botanical Garden Website

Liliaceae
At
Flora of North America
At
eFloras

A fragment containing Liriogamae
At
Resurrection of Themidaceae

NCBI Taxonomy Browser

{{Taxonbar, from=Q132925

Asparagales subfamilies