Sympetalae
Sympetally(fusedpetals) is a flower characteristic that historically was used to classify a grouping of plants termed Sympetalae, but this term has been abandoned in newer molecular based classifications, although the grouping has similarity to the modern termasterids.
History
[edit]
SympetalaeRchb.(1828), meaning “with fusedpetals”,is adescriptive botanical nameused in theEichler,Engler,andWettstein systemsfor a group offlowering plants(angiosperms).[1]In this group the flowers have a separatecalyxandcorollaand in which the corollapetalsare fused,[2]at least at their base, a condition known as sympetally.[3]
Prior to thephylogenicclassifications ofAugust Eichlerand his successors this group corresponds to theGamopetalaeofBentham and Hooker,gamopetally being asynonymof sympetally. This was one of the three divisions ofdicotyledonsin their system. In Eichler'sBlüthendiagramme,the class Dicotyleae was divided into two subclasses, the Sympetalae (also classified as Metachlamydeae) and theChoripetalae.[4]Adolf EnglerandKarl Prantlalso listed Sympetalae as a division of the class Dicotyledoneae in their system,Die Natürlichen Pflanzenfamilien,with Sympetalae being composed of gamopetalous families having gamopetalous corollas.[5]Alfred Rendlesimilarly described Sympetalae as originating fromdicots,and then divided them into Pentacyclicae and Tetracyclicae in accordance with the number of flower parts in each group, four and five respectively.[6]
According to Engler and Prantl, Sympetalae includes the following orders:Diapensiales,Ericales,Primulales,Plumbaginales,Ebenales,Contortae,Tubiflorae,Plantaginales,Rubiales,Cucurbitales,andCampanulatae.[7]
Sympetalous flowers are found in many angiosperms, but it was the combination of sympetally with a "stamen whorl isomerous and alternate with the corolla-lobes, or stamens fewer than the corolla lobes" thatTakhtajan(1964) used to define the subclassAsteridae,and later byCronquist(1981), and later, corresponding to theasteridsin the modernAngiosperm Phylogeny Group(APG) system, based onmolecular phylogenetics.Since sympetally has arisen independently many times in evolution (homoplasy), on its own it is not useful fortaxonomic classification.[8][3]
Examples
[edit]- Lady's bedstraw (Galium verum)
- Olive (Olea europaea)
- Northern highbush blueberry (Vaccinium corymbosum)
- Willow gentian (Gentiana asclepiadea)
- Lavender (Lavandula angustifolia)
- Jalap (Ipomoea purga)
See also
[edit]References
[edit]- ^Bihrmann 2020.
- ^Vuijk 2020.
- ^abErbar 1991.
- ^Sambamurty 2005,p. 15.
- ^Sambamurty 2005,p. 33.
- ^Sambamurty 2005,p. 16.
- ^Sambamurty 2005,p. 34.
- ^APG IV 2016.
Bibliography
[edit]- Sambamurty, A. V. S. S. (2005).Taxonomy of angiosperms.New Delhi: I.K. International.ISBN81-88237-16-7.
- Erbar, Claudia (26 July 1991)."Sympetaly - A systematic character?".Bot. Jahrb. Syst.112(4): 417–451.
- Angiosperm Phylogeny Group IV(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.
- Bihrmann."History of Taxonomy, 1875-1926".Caudiciforms.Retrieved17 July2020.
- Vuijk, Dick."Taxonomical notes on the grouping of plants".Natural history of Iceland.Retrieved18 July2020.