Orobanche elatior and O. kochii (Orobanchaceae) in Poland: distribution, taxonomy, plant communities and seed micromorphology

Abstract

Species of the genus <em>Orobanche</em> (Orobanchaceae), parasitic on <em>Centaurea</em> in Central Europe, were previously considered to belong to the <em>O. elatior</em> group. At present, the taxon is differentiated into two species, <em>O. elatior</em> Sutton and <em>O. kochii</em> F.W. Schultz. The paper presents for the first time the distribution of <em>O. elatior</em> and <em>O. kochii</em> in Poland based on a critical revision of herbarium and the literature data, as well as the results of field studies conducted between 1999 and 2014. The majority of the species’ localities are in south Poland: Silesia-Cracow, Małopolska and the Lublin Uplands. The distribution of both species in Poland is mapped and chronologically organized, and is thus the most recent in Europe. The taxonomy, host preferences, and ecology are also discussed. Seeds of both species were also investigated using light and scanning electron microscopy, which resulted in the designation of diagnostic features. The new color form of <em>O. kochii</em> f. <em>citrina</em> is described and illustrated. An account of all revised herbarium specimens collected from Poland, deposited in Poland and neighboring countries, is presented.