In plant parasitism, two groups can be distinguished based on two different mechanisms. The first group of parasitic plants includes those directly parasitizing on another plant. These plants are called haustorial parasites. Using a specialized organ, the haustorium, they attach themselves to other plants and uptake resources from the host’s vascular bundles. The second group comprises mycoheterotrophic plants, which parasitise fungi via mycorrhizal interactions and gain organic carbon from them. Plants in both groups display variable dependence on their host organism.
The functional categorization of parasitic plants has been a topic of an active debate that is still ongoing. The traditional categories are based on the ability to perform photosynthesis (photosynthetic hemiparasites and non-green holoparasites) and the location of the haustoria (root and stem parasites) (Heide-Jørgensen 2008). However, such a classification system struggles with phenomena such as rudimentary photosynthesis in some species, variable photosynthetic activity throughout the life cycle, and the existence of parasitic plants that integrate with their host to such an extent that they can be considered endophytic. For the functional classification of European parasitic plants, we have adopted the most recent classification system proposed by Teixeira-Costa & Davis (2021) with small further modifications. This system relies primarily on ontogenetic development and strategies of attachment to the host. The values of other important functional traits, including photosynthetic capacity, type of vascular bundle connection, development of the primary haustorium, and location of haustoria on the host are also well discriminated by the categories of Teixeira-Costa & Davis (2021).
In mycoheterotrophic plants, the initial developmental stages (gametophytes in lycophytes and ferns or belowground seedling stages of other plants) are not green, obtaining all their organic carbon and other resources from the fungus. The adult stages are still dependent on the mycorrhizal fungi as a source of water and mineral nutrients but vary in their dependence on heterotrophic carbon: there is a continuum from autotrophy, where the adult plants no longer use fungal carbon (this strategy is further called ‘initial mycoheterotrophy’), through mixotrophy (the adult plants combine autotrophic with heterotrophic nutrition; further called ‘partial mycoheterotrophy’), to heterotrophy (further called ‘full mycoheterotrophy’) (Merckx 2012). Two categories are distinguished here:
Těšitel, J., Těšitelová, T., Fahs, N., Blažek, P., Knotková, K. & Axmanová, I. (2023): Parasitism and mycoheterotrophy. – www.FloraVeg.eu.
Bellino, A., Alfani, A., Selosse, M.-A., Guerrieri, R., Borghetti, M., & Baldantoni, D. (2014). Nutritional regulation in mixotrophic plants: New insights from Limodorum abortivum. Oecologia, 175(3), 875–885. https://doi.org/10.1007/s00442-014-2940-8
Cameron, D. D., Preiss, K., Gebauer, G., & Read, D. J. (2009). The chlorophyll-containing orchid Corallorhiza trifida derives little carbon through photosynthesis. New Phytologist, 183(2), 358–364. https://doi.org/10.1111/j.1469-8137.2009.02853.x
Heide-Jørgensen, H. S. (2008). Parasitic flowering plants. Brill, Leiden.
Kubat, R. & Weber, H. C. (1987). Zur Biologie von Rhynchcorys elephas (L.) Griseb. (Scrophulariaceae). Beiträge zur Biologie der Pflanzen, 62, 239–250.
McNeal, J. R., Arumugunathan, K., Kuehl, J. V., Boore, J. L., & dePamphilis, C. W. (2007). Systematics and plastid genome evolution of the cryptically photosynthetic parasitic plant genus Cuscuta (Convolvulaceae). BMC Biology, 5(1), 55. https://doi.org/10.1186/1741-7007-5-55
Merckx, V. S. F. T. (Ed). (2012). Mycoheterotrophy: the biology of plants living on fungi. Springer, Berlin.
Miller, J. R., & Tocher, R. D. (1975). Photosynthesis and respiration of Arceuthobium tsugense (Loranthaceae). American Journal of Botany, 62(7), 765–769. https://doi.org/10.2307/2442068
Preiss, K., Adam, I. K. U., & Gebauer, G. (2010). Irradiance governs exploitation of fungi: Fine-tuning of carbon gain by two partially myco-heterotrophic orchids. Proceedings of the Royal Society B: Biological Sciences, 277(1686), 1333–1336. https://doi.org/10.1098/rspb.2009.1966
Rey, L., Sadik, A., Fer, A., & Renaudin, S. (1991). Trophic relations of the dwarf mistletoe Arceuthobium oxycedri with its host Juniperus oxycedrus. Journal of Plant Physiology, 138(4), 411–416. https://doi.org/10.1016/S0176-1617(11)80515-8
Schiebold, J. M.-I., Bidartondo, M. I., Lenhard, F., Makiola, A., & Gebauer, G. (2018). Exploiting mycorrhizas in broad daylight: Partial mycoheterotrophy is a common nutritional strategy in meadow orchids. Journal of Ecology, 106(1), 168–178. https://doi.org/10.1111/1365-2745.12831
Teixeira-Costa, L., & Davis, C. C. (2021). Life history, diversity, and distribution in parasitic flowering plants. Plant Physiology, 187(1), 32–51. https://doi.org/10.1093/plphys/kiab279
Těšitel, J. (2016). Functional biology of parasitic plants: A review. Plant Ecology and Evolution, 149(1), Article 1. https://doi.org/10.5091/plecevo.2016.1097
Těšitel, J., Těšitelová, T., Blažek, P., & Lepš, J. (2016). Parasitism and mycoheterotrophy.
www.pladias.cz.
Weber, H. C. (1973). Zur Biologie von Tozzia alpina L. (Standort, Wirtspflanzen, Entwicklung und Parasitismus). Beiträge zur Biologie der Pflanzen, 49, 237–249.
Zimmer, K., Meyer, C., & Gebauer, G. (2008). The ectomycorrhizal specialist orchid Corallorhiza trifida is a partial myco-heterotroph. New Phytologist, 178(2), 395–400. https://doi.org/10.1111/j.1469-8137.2007.02362.x
Carnivorous plants attract, trap and kill their prey, mainly insects, small crustaceans and protozoans, and subsequently absorb the nutrients from the dead bodies. Carnivorous species occur in environments with extremely low availability of nutrients, especially nitrogen and phosphorus, e.g. mires. In contrast, they usually have enough light (open habitats) and high water table or precipitation levels (Fleischmann et al. 2017). Therefore, the carnivory improves the intake of nutrients essential for growth but sparse in the environment, while the main source of energy for these plants is photosynthesis (Fleischmann et al. 2017).
Although there is a variety of morphological structures and trapping mechanisms, all the traps evolved as more or less complicated modifications of leaves with glandulous hairs (Hedrich & Fukushima 2021). Examples of active-hunting carnivorous plants include Aldrovanda with snap traps and Utricularia with suction traps. Typical representatives of the passive-trapping species can be found in the genera Drosera, Drosophyllum and Pinguicula, which have specific types of adhesive leaves. Another passive mechanism is the pitfall trap of Sarracenia (Hedrich & Fukushima 2021). Some species can combine adhesive traps with active movement of either glands or parts of the leaves (e.g. some species of Drosera).
The carnivory evolved independently in relatively distant lineages of angiosperms. There are carnivorous families within the orders Poales, Oxalidales, Caryophyllales, Ericales and Lamiales (Hedrich & Fukushima 2021). This convergent evolution of carnivory was possible because the traits associated with carnivorous syndrome from trap development through prey digestion to nutrient absorption are modifications of structures found also in non-carnivorous ancestors, where these originally served as defending mechanisms (Hedrich & Fukushima 2021).
In Europe, there are only three native carnivorous families, namely Droseraceae, Drosophyllaceae (order Caryophyllales), and Lentibulariaceae (Lamiales). Carnivorous plants have however often been planted and imported to Europe. Some of these non-native carnivorous species introduced to Europe can also survive in natural habitats and establish vital populations. For example, the species of Sarracenia (Sarraceniaceae, Ericales), native to North America, have nowadays scattered secondary occurrences across western and northwestern Europe.
Axmanová, I. (2023): Carnivory. – www.FloraVeg.eu.
Fleischmann, A., Schlauer, J., Smith, S. A., & Givnish, T. J. (2017). Evolution of carnivory in angiosperms. In Ellison, A. & Adamec, L. (Eds.), Carnivorous Plants: Physiology, ecology, and evolution (p. 22–41). Oxford University Press. https://doi.org/10.1093/oso/9780198779841.003.0003
Hedrich, R., & Fukushima, K. (2021). On the Origin of Carnivory: Molecular Physiology and Evolution of Plants on an Animal Diet. Annual Review of Plant Biology, 72(1), 133–153. https://doi.org/10.1146/annurev-arplant-080620-010429
Plants that are able to form a symbiosis with nitrogen-fixing bacteria are classified as nitrogen-fixing plants or nitrogen fixers. Specific bacteria are able to fix atmospheric nitrogen in a way to make it directly accessible to the plants (Franche et al. 2009). For providing nitrogen to the plant, the bacteria receive carbon in return (Crews, 1999, Dilworth et al., 2008). When forming a symbiosis with vascular plants, these bacteria usually inhabit the roots of their symbiont, forming so called (root-)nodules (Akkermans & Houwers, 1983, Fyson & Sprent, 1980, Loureiro et al., 1994). Three different symbiotic relationships between vascular plants and bacteria can be distinguished: (1) with the endosymbiotic cyanobacteria Nostoc, (2) with rhizobia (e.g. Allorhizobium, Bradyrhizobium, Mesorhizobium, Rhizobium and Sinorhizobium) and (3) with Frankia, so-called actinorhizal plants (Bond 1983, Pawlowski & Sprent 2007, Sprent 2008, Benson 2016, Tedersoo et al., 2018). Nitrogen fixation is not a completely phylogenetically conserved trait but evolved and disappeared a few times in the evolution of plants. For the first time it evolved in the Cycadales in Gymnosperms (symbiosis with cyanobacteria, plant species not native to Europe). Most of the nitrogen-fixing plants are however phylogenetically related and recruit from the so-called “Nitrogen-fixing clade” sensu Soltis et al. (1995). Only the family Zygophyllaceae (associated with rhizobia) and the non-native Gunnera, the only genus recorded in Europe associated with Nostoc, do not belong to this clade, representing the exceptions in Angiosperms. Only five native taxa (the genus Alnus, Hippophae rhamnoides, Myrica gale, Elaeagnus angustifolia and Coriaria myrtifolia) and some non-native species with sporadic occurrence are associated with Frankia in Europe. The largest number of nitrogen-fixing species form symbiosis with rhizobia. This includes almost all Fabaceae (uncertain genera and likely exceptions, respectively, are known only very few occurring in Europe: among others this includes Cercis, Erinacea, Gonocytisus, Hammatolobium, Podocytisus, Dorycnopsis (all native), Gleditsia, Cytisopsis, Styphnolobium, Gymnocladus (not native), plus Zygophyllaceae (with uncertain genera Balanites, Seetzenia and Tetraena occurring in Europe).
Assignment was done on the genus-level. Although rare cases of species-specific differences concerning the symbiotic nitrogen fixation status within one genus are known worldwide, for the European flora the general consent that the status is conserved on the genus level is still accepted. Assignment of “likely” or “unlikely” symbiosis with rhizobia is mainly based on their phylogenetic position where there has been no scientific study investigating the nitrogen fixation status of the genus directly or if studies showed diverging results.
Fahs, N., Blažek, P., Těšitel, J. & Axmanová, I. (2023). Symbiotic nitrogen fixation. – www.FloraVeg.eu.
Benson D. R. (2016). Frankia & actinorhizal plants. Available at https://frankia.mcb.uconn.edu/ [accessed on 1 Feb 2021]
Blažek, P. & Lepš, J. (2016). Symbiotic nitrogen fixation. – www.pladias.cz.
Bond, G. (1983). Taxonomy and distribution of non-legume nitrogen-fixing systems. In J. C. Gordon & C. T. Wheeler (Eds.), Biological nitrogen fixation in forest ecosystems: Foundations and applications (pp. 55–87). Springer Netherlands. https://doi.org/10.1007/978-94-009-6878-3_3
Crews, T. E. (1999). The presence of nitrogen fixing legumes in terrestrial communities: Evolutionary vs ecological considerations. Biogeochemistry, 46(1), 233–246. https://doi.org/10.1007/BF01007581
Dilworth M. J., James E. K., Sprent J. I., & Newton W. E. (Eds). (2008). Nitrogen-Fixing Leguminous Symbioses. Springer Netherlands.
Franche, C., Lindström, K., & Elmerich, C. (2009). Nitrogen-fixing bacteria associated with leguminous and non-leguminous plants. Plant and Soil, 321(1), 35–59. https://doi.org/10.1007/s11104-008-9833-8
Fyson, A., & Sprent, J. I. (1980). A Light and Scanning Electron Microscope Study of Stem Nodules in Vicia faba L. Journal of Experimental Botany, 31(123), 1101–1106.
Loureiro, M. F., DE Faria, S. M., James, E. K., Pott, A., & Franco, A. A. (1994). Nitrogen-fixing stem nodules of the Legume, Discolobium pulchellum Benth. The New Phytologist, 128(2), 283–295. https://doi.org/10.1111/j.1469-8137.1994.tb04012.x
Pawlowski, K., & Sprent, J. I. (2008). Comparison Between Actinorhizal And Legume Symbiosis. In K. Pawlowski & W. E. Newton (Eds.), Nitrogen-fixing Actinorhizal Symbioses (pp. 261–288). Springer Netherlands. https://doi.org/10.1007/978-1-4020-3547-0_10
Soltis, D. E., Soltis, P. S., Morgan, D. R., Swensen, S. M., Mullin, B. C., Dowd, J. M., & Martin, P. G. (1995). Chloroplast gene sequence data suggest a single origin of the predisposition for symbiotic nitrogen fixation in angiosperms. Proceedings of the National Academy of Sciences of the United States of America, 92(7), 2647–2651.
Sprent, J. I. (2008). Evolution and Diversity of Legume Symbiosis. In M. J. Dilworth, E. K. James, J. I. Sprent, & W. E. Newton (Eds.), Nitrogen-fixing Leguminous Symbioses (pp. 1–21). Springer Netherlands. https://doi.org/10.1007/978-1-4020-3548-7_1
Tedersoo, L., Laanisto, L., Rahimlou, S., Toussaint, A., Hallikma, T., & Pärtel, M. (2018). Global database of plants with root-symbiotic nitrogen fixation: NodDB. Journal of Vegetation Science, 29(3), 560–568. https://doi.org/10.1111/jvs.12627
Diagnostic species are characterized by a concentration of their occurrence in the stands belonging to the target vegetation unit while being rare or absent in other vegetation units. For the European vegetation classes of the EuroVegChecklist (Mucina et al. 2016), the list of these species was compiled from various European literature sources, especially syntaxonomic monographs and revisions containing extensive synthetic phytosociological tables. Expert opinion from EuroVegChecklist authors was used to judge problematic cases. Some species were assigned to more than one class. Unlike for the EUNIS habitat types, no statistical approach was used to determine diagnostic species for European vegetation classes.
Mucina L., Bültmann H., Dierßen K., Theurillat J.-P., Raus T., Čarni A., … Tichý L. (2016). Vegetation of Europe: Hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities. Applied Vegetation Science, 19(Suppl. 1), 3–264. https://doi.org/10.1111/avsc.12257 (Mucina et al. 2016, version 3, 2024-01-01)
Diagnostic species are characterized by a concentration of their occurrence in the stands belonging to the target habitat type while being rare or absent in other habitat types. For the habitat types of the EUNIS classification (Chytrý et al. 2020), these species were determined based on the calculation of fidelity of each species to a group of vegetation plots representing the target habitat type in a geographically and ecologically stratified selection of plots from the European Vegetation Archive (Chytrý et al. 2016). Fidelity was calculated using the phi coefficient of association (Sokal & Rohlf, 1995; Chytrý et al., 2002) standardized as if each habitat was represented by the same number of plots (Tichý & Chytrý, 2006). The species with a value of phi greater than 0.15 for a particular habitat were considered as diagnostic for this habitat. The statistical significance of the species–habitat association was tested using Fisher's exact test (Sokal & Rohlf, 1995), and if not significant at p < 0.05, the species was excluded from the list of diagnostic species (Tichý & Chytrý, 2006).
Chytrý, M., Tichý, L., Hennekens, S. M., Knollová, I., Janssen, J. A. M., Rodwell, J. S., … Schaminée, J. H. J. (2020). EUNIS Habitat Classification: expert system, characteristic species combinations and distribution maps of European habitats. Applied Vegetation Science, 23(4), 648–675. https://doi.org/10.1111/avsc.12519 – Version 2021-06-01: https://doi.org/10.5281/zenodo.4812736
Chytrý, M., Tichý, L., Holt, J., & Botta-Dukát, Z. (2002). Determination of diagnostic species with statistical fidelity measures. Journal of Vegetation Science, 13(1), 79–90. https://doi.org/10.1111/j.1654-1103.2002.tb02025.x
Chytrý, M., Hennekens, S. M., Jiménez-Alfaro, B., Knollová, I., Dengler, J., Jansen, F., … Yamalov, S. (2016). European Vegetation Archive (EVA): an integrated database of European vegetation plots. Applied Vegetation Science, 19(1), 173–180. https://doi.org/10.1111/avsc.12191
Sokal, R. R., & Rohlf, F. J. (1995). Biometry, 3rd edition. New York, NY: Freeman.
Tichý, L., & Chytrý, M. (2006). Statistical determination of diagnostic species for site groups of unequal size. Journal of Vegetation Science, 17(6), 809–818. https://doi.org/10.1111/j.1654-1103.2006.tb02504.x
Constant species are characterized by frequent occurrences in stands belonging to the target vegetation unit, but unlike diagnostic species, they can also commonly occur in other vegetation units. They were determined for the habitat types of the EUNIS classification (Chytrý et al. 2020) based on the calculation of the percentage frequency (constancy) of each species in a group of vegetation plots representing the target habitat type in a geographically and ecologically stratified selection of plots of all habitat types extracted from the European Vegetation Archive (Chytrý et al. 2016). The species with an occurrence frequency in the habitat type higher than 10% were considered as constant taxa.
Chytrý, M., Tichý, L., Hennekens, S. M., Knollová, I., Janssen, J. A. M., Rodwell, J. S., … Schaminée, J. H. J. (2020). EUNIS Habitat Classification: expert system, characteristic species combinations and distribution maps of European habitats. Applied Vegetation Science, 23(4), 648–675. https://doi.org/10.1111/avsc.12519 – Version 2021-06-01: https://doi.org/10.5281/zenodo.4812736
Chytrý M., Hennekens S.M., Jiménez-Alfaro B., Knollová I., Dengler J., Jansen F., … Yamalov S. (2016). European Vegetation Archive (EVA): an integrated database of European vegetation plots. Applied Vegetation Science, 19(1), 173–180. https://doi.org/10.1111/avsc.12191
Species association to broadly defined habitats is based on species occurrences reported for finer units, either vegetation types or habitats. We compiled available data from several sources, Sádlo et al. (2007), Mucina et al. (2016), Guarino et al. (2019). Final list of habitats include 18 broad habitats.
Axmanová, I. (2022). Broad habitat. – www.FloraVeg.EU.
Guarino, R., La Rosa, M. & Pignatti, S. (Eds) (2019). Flora d'Italia, volume 4. Bologna: Edagricole.
Mucina, L., Bültmann, H., Dierßen, K., Theurillat, J.-P., Raus, T., Čarni, A., … Tichý L. (2016). Vegetation of Europe: Hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities. Applied Vegetation Science, 19(Suppl. 1), 3–264. https://doi.org/10.1111/avsc.12257
Sádlo, J., Chytrý, M. & Pyšek, P. (2007). Regional species pools of vascular plants in habitats of the Czech Republic. Preslia, 79, 303–321.
No subordinate taxa were found for this item.