Pitcher plants
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The pitcher plants (Sarraceniaceae) are a family from the order of the heather-like (Ericales) with three genera in a little over twenty species. All species are new worldly and carnivorous plants (carnivorous or pre-carnivorous).
description
All species are perennial, herbaceous plants that form alternately arranged, tubular leaves out of a rhizome , usually in a native rosette , occasionally ( Heliamphora ) on an upright stem axis , which are used as traps for insect trapping.
The leaves are provided with a short petiole, stipules are missing. They are transformed into complex, more or less elongated, tubular, often can-like traps that are filled with a digestive fluid and on the side facing the axis a single or double wing bar ( Ala ) runs. At the extreme end of the side facing away from the axis, an often hood-like appendage attaches, the opening of the leaf is surrounded by a more or less clearly demarcated peristome . The leaves are covered with specialized glands on their outer and inner surfaces. Occasionally there are phyllodes .
The radial symmetry flowers are usually as a single flower on a terminal inflorescence, occasionally ( Heliamphora ) as a little-flowered, axillary grape . Pre-leaves are only available from Heliamphora . The flowers either consist of four to six, rarely threefold, bracts of a petal -like shape ( Heliamphora ) or they are differentiated into two petal circles, the sepals are then permanent, the petals are shed and are conspicuous. The ten to twenty or numerous stamens have short stamens , the ovary is uppermost, five- or rarely triple. The fruits are capsules with numerous small, winged seeds.
distribution
Pitcher plants are purely new worldly. Pitcher plants can be found in eastern to southeastern North America, the cobra lily in the northwest of the USA and the marsh jugs in the plateaus of the border area between Brazil, Venezuela and Guyana as well as in Venezuela in the adjacent Gran Sabana. All species colonize nutrient-poor locations.
Systematics and phylogenetics
The family includes three genera with around 25 species:
- Pitcher plants ( Sarracenia )
- Swamp Jugs ( Heliamphora )
- Cobra Lily ( Darlingtonia )
Molecular genetic studies yielded surprising results on the systematics of pitcher plants. On the one hand, it was shown that the pitcher plants themselves are not sister taxons of the cobra lily , but form a clade with the South American marsh jugs . On the other hand, there was a close relationship with the precarnivorous bedbug plants from South Africa .
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Paleobotany
In 1998/2001 fossils of a plant described in 2005 as Archaeamphora longicervia were discovered in China , which with high probability was considered to be a pitcher plant. The condition and completeness of the finds (only the flower, fruit and root system were missing) strengthened this interpretation. At over 125 million years old, it would have been one of the oldest known flowering plants and by far the oldest known carnivorous plant.
However, recent discoveries led to a different conclusion. According to this, it is not a separate species, but plant galls on the leaves of the conifer Liaoningocladus boii .
Individual evidence
Most of the information in this article has been taken from the sources given under references; the following sources are also cited:
- ↑ a b c d Klaus Kubitzki : Sarraceniaceae. In: Klaus Kubitzki (Ed.): The Families and Genera of Vascular Plants. Volume 6: Flowering Plants - Dicotyledons - Celastrales, Oxalidales, Rosales, Cornales, Ericales. Springer, Berlin et al. 2004, ISBN 3-540-06512-1 , pp. 422-425.
- ↑ Randall J. Bayer, Larry Hufford, Douglas E. Soltis : Phylogenetic Relationships in Sarraceniaceae Based on rbcL and ITS Sequences. In: Systematic Botany. Vol. 21, No. 2, 1996, ISSN 0363-6445 , pp. 121-134, JSTOR 2419743 .
- ↑ Hongqi Li: Early Cretaceous sarraceniacean-like pitcher plants from China. In: Acta Botanica Gallica. Vol. 152, No. 2, 2005, ISSN 1253-8078 , pp. 227-234, doi : 10.1080 / 12538078.2005.10515473 .
- ^ William Oki Wong, David Leonard Dilcher, Conrad C. Labandeira, Ge Sun, Andreas Fleischmann : Early Cretaceous Archaeamphora is not a carnivorous angiosperm. In: Frontiers in Plant Science. Vol. 6, 2015, ISSN 1664-462X , 326, doi : 10.3389 / fpls.2015.00326 .
