Gomphrenoids

The Gomphrenoideae are a subfamily of the Amaranthaceae.

The stamens have anthers with only one lobe (locule) and two pollen sacs. Many species show C₄-photosynthesis pathway.

The center of diversity lies in Central America, Mexico and the dry forests and thorn bush savannas of South America.

Systematics

The subfamily Gomphrenoideae was first published in 1893 by Hans Schinz (in: Engler und Prantl (Eds.): ''Die Natürlichen Pflanzenfamilien'' vol. 3, 1a, p. 97).

According to phylogenetic research by Sanchez Del-Pino (2009), the subfamily Gomphrenoideae Schinz is regarded as a monophyletic taxon with 19 genera and about 300-400 species. The traditional classification with two tribes (Gomphreneae and Pseudoplantageae) does not reflect the phylogenetic relationship in this group. Three clades can be recognized.:

Iresinoids

* '' Irenella'' Suess., with only one species:
** ''Irenella chrysotricha'' Suess., in rain forests of Ecuador. Phylogenetically, it falls within ''Iresine''.
* ''Iresine'' P.Browne (Syn.: ''Dicraurus'' Hook. f.): with about 45 species in North and South America.
* '' Woehleria'' Griseb.: with only one species
** ''Woehleria serpyllifolia'' Griseb., on mountain coasts of Cuba. Phylogenetically, it falls within ''Iresine''.
This is the sister clade of the two other clades.

Alternantheroids

* '' Alternanthera'' Forssk. (Syn.: ''Brandesia'' Mart.): with about 100-200 species, mainly in America, also in Africa and Australia.
* '' Pedersenia'' Holub: with about 10 species in tropical America.
* ''Tidestromia'' Standl.: with about 6 species in deserts of southern North America.
carbon fixation evolved independently in the genera ''Alternathera'', which also contains and – intermediate species, and ''Tidestromia''.

Gomphrenoids

* '' Blutaparon'' Raf. (Syn.: ''Philoxerus'' R.Br.): with about 5 species at shores of North and Middle America, West Africa, Micronesia and Japan, for example:
** '' Blutaparon rigidum''
* ''Froelichia'' Moench: with about 12 species in America.
* '' Froelichiella'' R.E.Fr., with only one species:
** ''Froelichiella grisea'' R.E.Fr. in Brasília.
* ''Gomphrena'' L. (Syn.: ''Bragantia'' Vand.): with about 90 species in America and about 30 species in Australia. This genus is polyphyletic, so taxonomical changes have to be expected.
** ''Gomphrena pulchella''
** ''Gomphrena decumbens''
** '' Gomphrena globosa''
* '' Gossypianthus'' Hook.: with 2 species in southern North America.
* ''Guilleminea'' Kunth (Syn.: ''Brayulinea'' Small)
* ''Hebanthe'' Mart.: with about 7 species in tropical America.
* ''Hebanthodes'' Pedersen, with only one species:
** ''Hebanthodes peruviana'' Pedersen in Peru.
* ''Lithophila'' Sw., with 2 species on Galapagos and the Caribic
* ''Pfaffia'' Mart.: with about 35 species in tropical America.
* '' Pseudogomphrena'' R.E.Fr.,with only one species:
** ''Pseudogomphrena scandens'' R.E.Fr. in Brasília.
* '' Pseudoplantago'' Suess.: with one species in Venezuela and one in Argentina.
* '' Quaternella'' Pedersen: with 3 species in Brasília.
* '' Xerosiphon'' Turcz.: with about 2 species in Brasília.
One large clade within this group, containing the genera ''Froelichia'', ''Guilleminea'', ''Blutaparon'', some ''Gomphrena'' species, and probably ''Gossypianthus'' and ''Lithophila'', has acquired the carbon fixation pathway. Some of these species occur at unusually high altitudes in the Andes, in cooler conditions than their relatives.

Photographs

File:Iresinelindenii.jpg, Iresinoids:
''Iresine lindenii''
File:Khaki weed (Alternanthera pungens) in Hyderabad, AP W IMG 8030.jpg, Alternantheroids: '' Alternanthera caracasana''
File:Tidestromia lanuginosa.jpg, Alternantheroids:
''Tidestromia lanuginosa''
File:Gomphrena serrata in Hyderabad W IMG 8870.jpg, Gomphrenoids: ''Gomphrena serrata''
File:Pfaffia glomerata-costapppr.jpg, Gomphrenoids:
''Pfaffia glomerata''

References

Kai Müller & Thomas Borsch (2005): ''Phylogenetics of Amaranthaceae using matK/trnK sequence data – evidence from parsimony, likelihood and Bayesian approaches'', In: ''Annals of the Missouri Botanical Garden'', 92, p. 66-102.
Ivonne Sánchez del-Pino, Thomas Borsch & Timothy J. Motley (2009): ''trnL-F and rpl16 Sequence Data and Dense Taxon Sampling Reveal Monophyly of Unilocular Anthered Gomphrenoideae (Amaranthaceae) and an Improved Picture of Their Internal Relationships'', In: ''Systematic Botany'', Volume 34 (1), p. 57-67.

{{taxonbar, from=Q142817

Amaranthaceae
Caryophyllales subfamilies