The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as cedar, celery-pine, cypress, fir, juniper, larch, pine, redwood, spruce, and yew, are included here. Some fossil conifers, however, belong to other distinct orders within the division Pinophyta.
(approximate number of species in parentheses)
Gymnosperm (Gymnospermae) taxonomy has been considered controversial, and lacks consensus. As taxonomic classification transformed from being based solely on plant morphology to molecular phylogenetics, the number of taxonomic publications increased considerably after 2008, however, these approaches have not been uniform. A taxonomic classification has been complicated by the relationship of extant to extinct taxa, and within extinct taxa, and particularly the placement of Gnetophyta. The latter have been variously classified as basal to all gymnosperms, sister group to conifers (‘gnetifer’ hypothesis) or sister to Pinaceae (‘gnepine’ hypothesis) in which they are classified within the conifers. While the extant gymnosperms form a monophyletic group, a formal name has not been assigned to this clade.
Gymnosperms are in a sister group relation to the Angiosperms (flowering plants) within the Spermatophytes (seed bearing plants), comprising four of the five major lineages of the latter. There are about 1000 extant gymnosperm species, distributed over about 12 families and 83 genera. Many of these genera are monotypic (41%), and another 27% are oligotypic (2–5 species).
- Pinophyta (conifers, 70, 600)
- Cycadophyta (cycads, 10, 300)
- Ginkgophyta (gingko, 1, 1)
- Gnetophyta (3, 100)
in which the Pinophyta include all conifers, extinct and extant, with Pinales representing all extant conifers.
Christenhusz and colleagues proposed a revised classification of gymnosperms in 2011, in which the above four subclades are treated as subclasses of class Equisetopsida s.l. sensu lato (sensu Chase & Reveal),[b] (also known as Embryophyceae nom. illeg.) which encompasses all land plants, as opposed to green algae, following their previous practice.
The system of Christenhusz et al, treats class Equisetopsida s.l. as having fourteen four subclasses, of which these four form the clade of gymnosperms;
In this scheme, the Pinidae comprise three orders, including Pinales;
However, the exact phylogeny remained a topic that was 'hotly debated", in particular whether the main lineages were best represented by the four subclasses of Christenhusz and colleagues or the more traditional five clades (cycads, ginkgos, cupressophytes, Pinaceae and gnetophytes). In 2014 the first complete molecular phylogeny was published, based on 90 species representing all extant genera. This established cycads as the basal group, followed by Ginkgoaceae, as sister to the remaining gymnosperms, and confirming the ‘gnepine’ hypothesis, as shown in this cladogram.
|Phylogeny of Gymnosperms|
- Cupressaceae (cypresses, juniper, redwood)
- Pinaceae (firs, pines, cedars, larch, spruce)
- Taxaceae (yews)
Subsequent revisions merged the Taxodiaceae and Cupressaceae, and placed Sciadopitys, formerly in Cupressaceae, into a separate family (Sciadopityaceae). Cephalotaxaceae had previously been recognized as a separate family, but was subsequently included in Taxaceae. Similarly Phyllocladaceae were included in Podocarpaceae. Yews (Taxaceae) have sometimes been treated as a separate order (Taxales).
Christenhusz and colleagues (2011) included only one family in Pinales, Pinaceae, a practice subsequently followed by the Angiosperm Phylogeny Website and the Gymnosperm Database. In this restricted model Pinales (Pinaceae) comprisea 11 genera and about 225 species, all of the other conifers originally included in this order, being included in other orders such as Cupressales.
- Eckenwalder, James E. (2009). Conifers of the World: The Complete Reference. Timber Press. ISBN 978-0-88192-974-4.
- Engler, Adolf; Prantl, Karl, eds. (1924) [1887–1915]. Die natürlichen Pflanzenfamilien nebst ihren Gattungen und wichtigeren Arten, insbesondere den Nutzpflanzen, unter Mitwirkung zahlreicher hervorragender Fachgelehrten (in German). 21 parts (Abteilungen) (2nd ed.). Berlin: Duncker & Humblot.CS1 maint: ref=harv (link), see also Die Natürlichen Pflanzenfamilien
- Debreczy, Zsolt; Rácz, István (2011). Conifers Around the World: Conifers of the Temperate Zones and Adjacent Regions. DendroPress. ISBN 978-963-219-061-7.
- Farjon, Aljos (2001) . World Checklist and Bibliography of Conifers (2nd ed.). Royal Botanic Gardens, Kew. ISBN 978-1-84246-025-2.
- — (2010). A Handbook of the World's Conifers (2 Vols.). Brill. ISBN 90-04-17718-3.
- —; Filer, Denis (2013). An Atlas of the World's Conifers: An Analysis of their Distribution, Biogeography, Diversity and Conservation Status. Brill. ISBN 978-90-04-21181-0.
- Plomion, Christophe; Bousquet, Jean; Kole, Chittaranjan, eds. (2011). Genetics, Genomics and Breeding of Conifers. CRC Press. ISBN 978-1-57808-719-8.
- Delevoryas, T (13 April 2015). "Gymnosperm". Encyclopædia Britannica. Retrieved 6 August 2020.CS1 maint: ref=harv (link)
- Eckenwalder, James Emory (3 September 2008). "Conifer". Encyclopædia Britannica. Retrieved 27 July 2020.CS1 maint: ref=harv (link)
- Chase, Mark W; Reveal, James L (2009). "A phylogenetic classification of the land plants to accompany APG III". Botanical Journal of the Linnean Society. 161 (2): 122–127. doi:10.1111/j.1095-8339.2009.01002.x.
- Christenhusz, M. J. M.; Reveal, J. L.; Farjon, A.; Gardner, M. F.; Mill, R. R.; Chase, M. W. (18 February 2011). "A new classification and linear sequence of extant gymnosperms" (PDF). Phytotaxa. 19 (1): 55–70. doi:10.11646/phytotaxa.19.1.3.
- De La Torre, Amanda R.; Piot, Anthony; Liu, Bobin; Wilhite, Benjamin; Weiss, Matthew; Porth, Ilga (January 2020). "Functional and morphological evolution in gymnosperms: A portrait of implicated gene families". Evolutionary Applications. 13 (1): 210–227. doi:10.1111/eva.12839.
- Farjon, Aljos (26 March 2018). "The Kew Review: Conifers of the World". Kew Bulletin. 73 (1). doi:10.1007/s12225-018-9738-5.
- Lu, Ying; Ran, Jin-Hua; Guo, Dong-Mei; Yang, Zu-Yu; Wang, Xiao-Quan (15 September 2014). "Phylogeny and Divergence Times of Gymnosperms Inferred from Single-Copy Nuclear Genes". PLoS ONE. 9 (9): e107679. doi:10.1371/journal.pone.0107679.
- Ran, Jin-Hua; Shen, Ting-Ting; Wang, Ming-Ming; Wang, Xiao-Quan (27 June 2018). "Phylogenomics resolves the deep phylogeny of seed plants and indicates partial convergent or homoplastic evolution between Gnetales and angiosperms". Proceedings of the Royal Society B: Biological Sciences. 285 (1881): 20181012. doi:10.1098/rspb.2018.1012.
- Ran, Jin-Hua; Shen, Ting-Ting; Wu, Hui; Gong, Xun; Wang, Xiao-Quan (December 2018). "Phylogeny and evolutionary history of Pinaceae updated by transcriptomic analysis". Molecular Phylogenetics and Evolution. 129: 106–116. doi:10.1016/j.ympev.2018.08.011.
- Wang, Xiao-Quan; Ran, Jin-Hua (June 2014). "Evolution and biogeography of gymnosperms". Molecular Phylogenetics and Evolution. 75: 24–40. doi:10.1016/j.ympev.2014.02.005.
- Stevens, P.F. (2020) . "Pinales". AP Web v. 14. Missouri Botanical Garden. Retrieved 28 July 2020.CS1 maint: ref=harv (link) (see also Angiosperm Phylogeny Website)
- Earle, Christopher J. (2020). "The Gymnosperm Database".
- Nagalingum, Nathalie; Burleigh, Gordon (2018). "The Gymnosperm Phylogeny Group". Botany 2018 (Abstract). Botanical Society of America. Retrieved 30 July 2020.
- Eckenwalder, James E (2007). "Gymnosperm classification". Flora of North America. Volume 1, Chapter 13. Retrieved 11 August 2020.