Morphologically distinguishable species of Portulaca oleracea s. l. determined on the basis of varnish impressions of the seeds
DOI:
https://doi.org/10.21248/kochia.v16.165Abstract
Depending on the taxonomic concept, Portulaca oleracea is considered as a species that can be divided into infraspecific taxa or as an aggregate with several species. These can be distinguished and identified morphologically almost solely on the basis of the sculpture of the flat (lateral) sides of the seeds. Because of disturbing reflections on the more or less shiny seed coats, the fine structures are difficult or impossible to recognise under the binocular with reflected light illumination. However, varnish prints provide images in the transmitted light microscope that can almost compete with scanning electron microscopic images and can greatly facilitate the determination. The method was used in a first floristic inventory focusing on Rhineland-Palatinate (Germany). A taxonomic concept is advocated, which assigns the previous findings to 4 wild species and one cultivated species. There are still open questions concerning nomenclature and typification.
References
Amini Rad, M., Sajedi, S. & Domina, G. 2017: First data on the taxonomic diversity of the Portulaca oleracea aggregate (Portulacaceae) in Iran. – Turk. J. Bot. 41: 535–541. https://doi.org/10.3906/bot-1611-43
Bock, H. 1546: Kreuterbuch, ed. 2. – Straßburg: Wendel Rihel J.
Bomble, F. W. 2013: Funde von Portulaca granulatostellulata, P. nitida und P. papillato-stellulata in Nordrhein-Westfalen. – Veröff. Bochum. Bot. Ver. 5: 36–43.
Bulakh, O. V., Shevera, M. V., Szkudlarz, P, Bulakh, P. Y. & Celka, Z. 2022: Identification of new taxa of Portulaca oleracea L. aggregate from Poland based on seed coat micromorphological characteristics. – Acta Soc. Bot. Poloniae 91: 9118. https://doi.org/10.5586/asbp.9118
Danin, A., Baker, I. & Baker, H. G. 1979 „1978“: Cytogeography and taxonomy of the Portulaca oleracea L. polyploid complex. – Israel J. Bot. 27: 177–211.
Danin, A. & Bagella, S. 2012: A new cultivar microspecies of the Portulaca oleracea aggregate from the E Mediterranean. – Willdenowia 42: 63–65. https://doi.org/10.3372/wi42.42106
Danin, A., Domina, G, & Raimondo, F. M. 2008: Microspecies of the Portulaca oleracea aggregate found on major Mediterranean islands (Sicily, Cyprus, Crete, Rhodes). – Fl. Medit. 18: 89–107.
Danin, A. & Fragman-Sapir, O. 2016: Flora of Israel and adjacent regions. – https://flora.org.il/en/ plants, aufgerufen im Januar 2023.
Driesen, H. H. 1955: Das Lackabdruckverfah ren in der mikroskopischen Technik. – Mikrokosmos 44: 238–240.
El-Bakatoushi, R., Alframawy, A. M., Sa mer, M., El-Sadek, L. & Botros, W. 2013: Evolution of the Portulaca oleracea L. aggregate in Egypt on molecular and phenotypic levels revealed by morphology, inter-simple sequence repeat (ISSR) and 18S rDNA gene sequence markers. – Flora 208: 464–477. https://doi.org/10.1016/j.flora.2013.07.008
Geesink, R. 1969: An account of the genus Portulaca in Indo-Australia and the Pacific (Portulacaceae). – Blumea 17: 275–301.
Haworth, A. H. 1803: Dissertatio tertia. Enumeratio plantarum generis Portulaca. – p. 128–134. In: Miscellanea Naturalia sive Dissertationes varias ad Historiam Natura liem spectans. – London: J. Taylor.
Legrand, C. D. 1962: Las especies americanas de Portulaca. – Anales Mus. Hist. Nat. Montevideo 7(3).
L’Obel, M. 1581: Plantarum seu stirpium icones. – Antwerpen: Christopheri Plantini.
Matthews, J. F. & Levins, P. A. 1986: The Systematic Significance of seed morphology in Portulaca (Portulacaceae) under scan ning electron microscopy. – Syst. Bot. 11: 302–308.
Poellnitz, K. von 1936: Versuch einer Monographie der Gattung Portulaca. – Repert. Spec. Nov. Regni Veg. 37: 240–320.
Pohl, D. 1999: Mikroskopie lichtundurchlässiger Objekte mittels Lackabdruck. – Mikrokosmos 88: 277–281.
Ricceri, C. & Arrigoni, C. V. 2000: L’aggregato di Portulaca oleracea L. (Portulacaceae) in Italia. – Parlatorea 4: 91–97.
Uotila, P., Sennikov, A. N. & Danin, A. 2012: The nomenclature of Portulaca oleracea and P. sativa (Portulacaceae). – Willdenowia 42: 25–28. https://doi.org/10.3372/wi42.42102
Vekslyarska, T. 2011: Ploidie- und Samengrößenvariation im Portulaca oleracea-Aggregat. – Diplomarbeit Universität Wien.
Walter, J. 2008: Portulak / Portulaca. – p. 370. In: Fischer, M. A., Oswald, K. & Adler, W.: Exkursionsflora für Österreich, Liechtenstein und Südtirol, ed. 3. – Linz: Biologiezentrum der Oberösterreichischen Landesmuseen.
Walter, J., Vekslyarska, T. & Dobeš, C. 2015: Flow cytometric, chromosomal and morphometric analyses challenge current taxonomic concepts in the Portulaca oleracea complex (Portulacaeae, Caryophyllales). – Bot. J. Linn. Soc. 179: 144–156.
