Rosids

The rosids are members of a large clade (monophyletic group) of flowering plants, containing about 70,000 species,[2] more than a quarter of all angiosperms.[3]

Rosids Temporal range: Cretaceous–recent
Euphorbia heterophylla
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Superrosids
Clade:	Rosids
Orders[1]
Vitales Eurosids Fabids Zygophyllales Celastrales Oxalidales Malpighiales Fabales Rosales Cucurbitales Fagales Malvids Geraniales Myrtales Crossosomatales Picramniales Sapindales Huerteales Malvales Brassicales

The clade is divided into 16 to 20 orders, depending upon circumscription and classification. These orders, in turn, together comprise about 140 families.[4]

Fossil rosids are known from the Cretaceous period. Molecular clock estimates indicate that the rosids originated in the Aptian or Albian stages of the Cretaceous, between 125 and 99.6 million years ago.[5][6]

Name

The name is based upon the name "Rosidae", which had usually been understood to be a subclass. In 1967, Armen Takhtajan showed that the correct basis for the name "Rosidae" is a description of a group of plants published in 1830 by Friedrich Gottlieb Bartling.[7] The clade was later renamed "Rosidae" and has been variously delimited by different authors. The name "rosids" is informal and not assumed to have any particular taxonomic rank like the names authorized by the ICBN. The rosids are monophyletic based upon evidence found by molecular phylogenetic analysis.

Three different definitions of the rosids were used. Some authors included the orders Saxifragales and Vitales in the rosids.[8] Others excluded both of these orders.[9] The circumscription used in this article is that of the APG IV classification, which includes Vitales, but excludes Saxifragales.

Relationships

The rosids and Saxifragales form the superrosids clade.[2][9] This is one of three groups that compose the Pentapetalae (core eudicots minus Gunnerales),[10] the others being Dilleniales and the superasterids (Berberidopsidales, Caryophyllales, Santalales, and asterids).[9]

Classification

The rosids consist of two groups: the order Vitales and the eurosids (true rosids). The eurosids, in turn, are divided into two groups: fabids (Fabidae, eurosids I) and malvids (Malvidae, eurosids II).[9]

Orders

The rosids consist of 17 orders. In addition to Vitales, there are 8 orders in fabids and 8 orders in malvids. Some of the orders have only recently been recognized.[9] These are Vitales,[11] Zygophyllales,[12] Crossosomatales,[13] Picramniales,[14] and Huerteales.[15]

Phylogeny

The phylogeny of rosids shown below is adapted from the Angiosperm Phylogeny Group website.[9]

rosids	Vitales   eurosids  fabids    Zygophyllales     COM clade    Celastrales       Malpighiales     Oxalidales       nitrogen‑fixing clade    Fabales       Rosales       Fagales     Cucurbitales             malvids     Geraniales     Myrtales         Crossosomatales       Picramniales       Sapindales       Huerteales       Brassicales     Malvales

The nitrogen-fixing clade contains a high number of actinorhizal plants (which have root nodules containing nitrogen fixing bacteria, helping the plant grow in poor soils). Not all plants in this clade are actinorhizal, however.[16]

References

1. Angiosperm Phylogeny Group (2016). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV". Botanical Journal of the Linnean Society. 181 (1): 1–20. doi:10.1111/boj.12385.
2. Wang, Hengchang; Moore, Michael J.; Soltis, Pamela S.; Bell, Charles D.; Brockington, Samuel F.; Alexandre, Roolse; Davis, Charles C.; Latvis, Maribeth; Manchester, Steven R.; Soltis, Douglas E. (10 March 2009), "Rosid radiation and the rapid rise of angiosperm-dominated forests", Proceedings of the National Academy of Sciences, 106 (10): 3853–8, Bibcode:2009PNAS..106.3853W, doi:10.1073/pnas.0813376106, PMC 2644257, PMID 19223592
3. Scotland, Robert W.; Wortley, Alexandra H. (2003), "How many species of seed plants are there?", Taxon, 52 (1): 101–4, doi:10.2307/3647306, JSTOR 3647306
4. Soltis, Douglas E.; Soltis, Pamela S.; Peter K. Endress; Mark W. Chase (2005), Phylogeny and Evolution of the Angiosperms, Sunderland, MA, USA: Sinauer, ISBN 978-0-87893-817-9
5. Davies, T.J.; Barraclough, T.G.; Chase, M.W.; Soltis, P.S.; Soltis, D.E.; Savolainen, V. (2004), "Darwin's abominable mystery: Insights from a supertree of the angiosperms", Proceedings of the National Academy of Sciences, 101 (7): 1904–9, Bibcode:2004PNAS..101.1904D, doi:10.1073/pnas.0308127100, PMC 357025, PMID 14766971
6. Magallón, Susana; Castillo, Amanda (2009), "Angiosperm diversification through time", American Journal of Botany, 96 (1): 349–365, doi:10.3732/ajb.0800060, PMID 21628193
7. Reveal, James L. (2008), "A Checklist of Family and Suprafamilial Names for Extant Vascular Plants", Home page of James L. Reveal and C. Rose Broome
8. Burleigh, J. Gordon; Hilu, Khidir W.; Soltis, Douglas E. (2009), File 7, "Inferring phylogenies with incomplete data sets: a 5-gene, 567-taxon analysis of angiosperms" (PDF), BMC Evolutionary Biology, 9: 61, doi:10.1186/1471-2148-9-61, PMC 2674047, PMID 19292928
9. Stevens, Peter F. (2001), Angiosperm Phylogeny Website
10. Cantino, Philip D.; Doyle, James A.; Graham, Sean W.; Judd, Walter S.; Olmstead, Richard G.; Soltis, Douglas E.; Soltis, Pamela S.; Donoghue, Michael J. (2007), "Towards a phylogenetic nomenclature of Tracheophyta" (PDF), Taxon, 56 (3): 822–846, doi:10.2307/25065865, JSTOR 25065865
11. Reveal, James L. (1995), "Newly required suprageneric names in vascular plants", Phytologia, 79 (2): 68–76 See p. 72
12. Chalk, L. (1983), "Wood structure", in Metcalfe, C.R.; Chalk, L. (eds.), Wood Structure and Conclusion of the General Introduction, Anatomy of the Dicotyledons, II (2nd ed.), Clarendon Press, pp. 1-51 [1-2 by C. R. Melcalfe], ISBN 978-0-19-854559-0
13. Kubitzki, Klaus, ed. (2007), "Introduction to Crossosomatales", Flowering Plants. Eudicots: Berberidopsidales, Buxales, Crossosomatales, Fabales p.p., Geraniales, Gunnerales, Myrtales p.p., Proteales, Saxifragales, Vitales, Zygophyllales, Clusiaceae Alliance, Passifloraceae Alliance, Dilleniaceae, Huaceae, Picramniaceae, Sabiaceae, The Families and Genera of Vascular Plants, IX, Springer, ISBN 978-3-540-32219-1
14. Hutchinson, John (1979) [1973], The Families of Flowering Plants (3rd ed.), Oxford University Press, ISBN 9783874291606
15. Worberg, Andreas; Alford, Mac H.; Quandt, Dietmar; Borsch, Thomas (2009), "Huerteales sister to Brassicales plus Malvales, and newly circumscribed to include Dipentodon, Gerrardina, Huertea, Perrottetia, and Tapiscia", Taxon, 58 (2): 468–478, doi:10.1002/tax.582012
16. Wall, L. (2000), "The actinorhizal symbiosis", Journal of Plant Growth and Regulation, 19 (2): 167–182, doi:10.1007/s003440000027, PMID 11038226

External links

• Media related to Rosids at Wikimedia Commons