Dagmara Kwolek

Orobanche grenieri (Orobanchaceae), a Southwestern European Species Newly Found in Asia

We report occurrences of Orobanche grenieri (Orobanchaceae) in the Lesser Caucasus in southern Georgia (western Asia), and in Badakhshan in Tajikistan (central Asia). These localities are more than 3000 and 5000 km apart from its previously known distribution areas in Spain and France, respectively. We used morphological evidence as well as nuclear ribosomal ITS and plastid rbcL sequences to test the taxonomic assignment of the Georgian plants to O. grenieri and to determine their phylogenetic position. We list the features that differentiate O. grenieri from morphologically similar species, provide illustrations, a distribution map, and we propose an IUCN conservation status for the Georgian populations.

Reinterpretation of Potamogeton ×nerviger: solving a taxonomic puzzle after two centuries

Hybrids form an important component of Potamogeton diversity but their exact taxonomic identities and distributions are often insufficiently known. Potamogeton nerviger was described from Lithuania in 1827 as a proper species. Based on morphological and anatomical characters, its interpretation has since varied, ranging from synonymization with other species to identification as different hybrids and intraspecific taxa. Currently, it is universally recognized as the hybrid P. alpinus × P. lucens. Using a combined molecular, morphological and anatomical investigation we re-examined the identity of P. ×nerviger, based on both original and recent plant material. We report a successful amplification and sequencing of nuclear ribosomal ITS1 region from a 188year-old type collection. This was shown to be genetically identical to the morphologically matching plants recently collected at the type locality. Comparison with molecular characters of the possible parental species shows that P. ×nerviger is not P. alpinus × P. lucens, as currently believed, but another hybrid, P. nodosus × P. perfoliatus, which is currently called P. ×assidens. This molecular identification is also supported by anatomical evidence. In contrast, the actual existence of the hybrid P. alpinus × P. lucens is doubtful. Consequences for nomenclature and identities of records reported from other sites are discussed.

First Report of Dodder (Cuscuta epithymum) Parasitizing Hemiparasitic Species of Santalaceae (Thesium) and Orobanchaceae (Euphrasia, Melampyrum, Odontites, Orthantha, and Rhinanthus) in Poland

Cuscuta epithymum L. (Convolvulaceae) is native to Europe, western Asia, and northern Africa but occurs worldwide and infects many crops, especially legumes, as well as wild plants. Epiparasites (also called hyperparasites) are parasitic plants that parasitize other parasitic plants of a different species. Epiparasitism in world flora is known only within Viscaceae and rarely in Santalaceae and Eremolepidaceae (Calvin and Wilson 2009). Field surveys conducted in southern Poland in May to September 2015 and 2016 revealed parasitic attachment of the holoparasitic Cuscuta epithymum on the shoots of several hemiparasitic species: Thesium linophyllon (Santalaceae) and Odontites serotina, Orthantha lutea, Melampyrum arvense, Euphrasia stricta, and Rhinanthus glaber (Orobanchaceae). These occurred in four localities located in the Nida Basin (Malopolska Upland): Kikow, Sedziejowice, Skowronno, and Samostrzalow, in xerothermic grasslands, old quarries, and on the edges of cultivated fields in Solec-Zdroj (50°22′05″N, 20°51′27″E), Chmielnik (50°34′21″N, 20°39′45″E), Pinczow (50°32′21″N, 20°30′34″E), and Kije (50°35′29″N, 20°38′32″E) counties (altitude: 250 to 287 m above sea level). The surveyed area covered about 600 m², and the epiparasitic incidence was 30 to 50% total parasitism of all hemiparasitic species. The dodder population covered 20 to 80% of shoots of these hemiparasitic species, especially T. linophyllon. The host plants parasitized by the dodder showed poor growth, and their leaves became chlorotic. The epiparasites spread aggressively in the primary tissues of the host, particularly in its stems and leaves, as well as inflorescences. The main botanical features of the dodder were as follows: (i) stem 0.2 to 0.4 mm, thready, reddish to purplish, rootless, leafless, with short haustoria; (ii) inflorescence compact, spherical, ∼20 flowered; (iii) flowers sessile, white, pink to purplish, 2 to 3 mm long, with five sepals and petals; and (iv) fruits, globose capsule with usually four small seeds, ∼1 mm. For phylogenetic study the total genomic DNA was extracted, and the internal transcribed spacer (ITS) region was amplified and sequenced using the ITS7A (Aguilar et al. 1999) and ITS4 (White et al. 1990) primers. The obtained 624-bp long ITS region sequence was deposited in GenBank (accession no. KY707298). The sequence showed the highest similarity (99%) to sequences of C. epithymum (DQ924606, DQ924605, and DQ924609). To our knowledge, this is the first report of holoparasitic C. epithymum as an epiparasite on hemiparasitic species of Santalaceae and Orobanchaceae, and simultaneously the first report of epiparasitism in Convolvulaceae, representing a unique phenomenon in epiparasitism worldwide. C. epithymum, if left unabated, affects yield or influences chemical composition of infected host-parasites used therapeutically, because of dodder toxicity aspect, and thereby the medical properties of any commercial-scale production hemiparasites (especially the widely used herb Euphrasia) in the future. Epiparasitism could limit the negative effect of the parasite on the primary host (Kuijt and Lye 2005). The epiparasite may harm the host parasite relatively more than the same parasite would harm a nonparasitic host (Heide-Jorgensen 2008).