Stone breakers
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Sedum saxifrage ( Saxifraga aizoides ) |
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The saxifrage-like (Saxifragales) are an order of the flowering plant (Magnoliopsida).
description
Since this order brings together families that belong together in terms of molecular genetics, there are few morphological similarities.
In this order there is a wide variety of growth forms from annuals to perennial herbaceous plants to shrubs and trees . Some species are succulents . Two types are root parasites . There are also some aquatic plants . Usually the leaves are alternate. Stipules are often present, but not, for example, in the Crassulaceae.
The flowers are usually five-fold. The bracts are clearly differentiated into sepals and petals. The carpels are primarily free (eg. Crassulaceae ) with a tendency to coalescence - coenocarper ovary (eg. Saxifragaceae ). Often the ovaries are half to completely subordinate. The pollen grains often have a grooved surface.
Systematics
To order the saxifrage-like (Saxifragales) is within the Kerneudikotyledonen the sister group of Rosids clade . The following families are counted to it:
- Altingiaceae
- Aphanopetalaceae
- Cercidiphyllaceae
- Thick-leaf family (Crassulaceae)
- Daphniphyllaceae
- Gooseberry Family (Grossulariaceae)
- Millennial family (Haloragaceae)
- Witch Hazel Family (Hamamelidaceae)
- Iteaceae , including Pterostemonaceae
- Peonies (Paeoniaceae)
- Penthoraceae
- Peridiscaceae , including Medusandraceae and Soyauxia
- Saxifragaceae (Saxifragaceae)
- Tetracarpaeaceae
Cladogram according to the AP website:
| Saxifragales |
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In the order of the Saxifragales, the positions of the individual families are clearly documented by molecular genetic data. In the past, however, these families were integrated into completely different orders, because they differ greatly in their morphology. Earlier that were about Saxifragaceae (Saxifragaceae) to order the rose-like counted (Rosales). The chlorophyll-free root parasites of the Cynomoriaceae have not yet found a place in the above cladogram. The woody Peridiscaceae are isolated in this cladogram. The woody taxa Paeoniaceae, Altingiaceae, Hamamelidaceae, Cercidiphyllaceae, Daphniphyllaceae form a secured clade. The families Crassulaceae, Aphanopetalaceae, Tetracarpaeaceae, Penthoraceae, Haloragaceae also form a secured clade. Pterostemonaceae with Iteaceae and Grossulariaceae with Saxifragaceae are sister groups and together form a clade.
Web links
- Entry in the Tree of Life project. (English)
literature
- The order of the Saxifragales on the AP website. (Section systematics)
- Andreas Bresinsky , Christian Körner , Joachim W. Kadereit , Gunther Neuhaus , Uwe Sonnewald : Textbook of botany . Founded by Eduard Strasburger . 36th edition. Spektrum Akademischer Verlag, Heidelberg 2008, ISBN 978-3-8274-1455-7 , p. 877 . (Sections systematics and description)
Individual evidence
- ↑ Angiosperm Phylogeny Group : An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. In: Botanical Journal of the Linnean Society. Volume 161, No. 2, 2009, pp. 105-121, DOI: 10.1111 / j.1095-8339.2009.00996.x .