Euphrasia Stricta Research Articles

Phenolic acids as chemotaxonomic markers able to differentiate the Euphrasia species

The objective of this study was to get the answer on the question, which phenolic compounds may serve as chemical markers in taxonomy of Euphrasia spp. (E. nemorosa, E. rostkoviana, E. stricta) collected from the wild. Moreover, it is still unknown how and which environmental parameters can impact on the quantity of polyphenols, flavonoids and phenolic acids. To the authors’ knowledge, this is the first study that analyses such a broad spectrum of phenolic compounds in the genus Euphrasia and takes into account the habitat conditions of their synthesis. The species of Euphrasia differ significantly in the content of phenolic compounds. Euphrasia rostkoviana has the highest total content of polyphenols and flavonoids. Euphrasia stricta contains the largest amounts of phenolic acids, such as 5-O-caffeoylquinic, p-coumaric, protocatechuic and salicylic acid. It has been evidenced that the content of metabolites in the Euphrasia herb depends on a number of habitat parameters. The increased content of phenolic acids in E. stricta can be attributed to the fact that this species occupies drier habitats, with lower content of nitrogen and organic carbon compared to E. nemorosa and E. rostkoviana. The compounds that can be considered as chemotaxonomic markers are salicylic and protocatechuic acid for E. stricta, 5-O-caffeoylquinic acid for E. rostkoviana and ferulic acid for E. nemorosa. These findings provide theoretical and empirical basis for a chemotaxonomic classification of those species, which taken together with morphological characteristics should prevent misidentification.

Catalogue and Typifications of New Taxa of Vascular Plants Described by Mårten Magnus Wilhelm Brenner (1843–1930)

Mårten Magnus Wilhelm Brenner (1843–1930) was a non-professional Finnish botanist who published 220 articles or notes. Brenner worked on East Fennoscandian vascular plants (the territory of present-day Finland and adjacent Russia). He validly published ca. 833 new taxa, especially in genus Hieracium (including Pilosella), and introduced 56 names as nomina nuda. Brenner had no concept of type specimens and therefore all his plant taxa need typification, and 151 of those are lectotypified here. In this paper, nomina nuda and the taxa whose type material was not found are also listed, except those of the apomictic genera Hieracium and Taraxacum. Many of Brenner's new taxa are forms and varieties, generally not recognised nowadays. Many of his taxa were based on single or few specimens and therefore were characterised by local distributions, whereas some include ample original material. Finnish botanists generally ignored Brenner's contributions to taxonomy. However, 11 species of Hieracium, 20 of Taraxacum and Euphrasia stricta var. tenuis (Brenner) Jalas are currently recognised, and recently also E. wettsteinii var. botniensium (Brenner) Piirainen. Together Brenner's type collection treated here consists of 254 sheets (Hieracium and Taraxacum excluded), deposited at the Botanical Museum (H), Finnish Museum of Natural History, University of Helsinki, Finland.

New alternate hosts for Cronartium spp.: Odontites, Euphrasia, Rhinanthus and Papaver

AbstractSusceptibility of 13 plant species to Scots pine blister rust, Cronartium flaccidum, or white‐pine blister rust, Cronartium ribicola, was tested in Finland. The test species belonged to 10 genera in eight plant families, and they were inoculated in the laboratory or in the glasshouse. After 8 weeks of incubation, C. flaccidum sporulated on five species and provenances in the glasshouse and six species in the laboratory. After similar incubation, C. ribicola sporulated on one species in the glasshouse and two species in the laboratory. Cronartium ribicola formed uredinia and telia on Euphrasia nemorosa in the glasshouse and uredinia on E. nemorosa and Ribes nigrum in the laboratory. Cronartium flaccidum produced uredinia and telia on Odontites verna (two provenances), E. nemorosa and Euphrasia stricta both in the glasshouse and in the laboratory, on Papaver rhoeas in the glasshouse, and on Rhinanthus serotinus, Impatiens parviflora and Paeonia lactiflora in the laboratory. Rhinanthus serotinus, O. verna, I. parviflora and P. rhoeas are new alternate hosts for C. flaccidum, and for the first time, species of Odontites and Papaver were confirmed by molecular methods as alternate hosts for the rust. Cronartium ribicola was reported to sporulate on E. nemorosa for the first time. In conclusion, hemiparasitic genera of the family Orobanchaceae contain several forest species that are susceptible to C. flaccidum, although single highly resistant species also occur in these genera. Similarly, several genera of Orobanchaceae contain single species that are susceptible to C. ribicola, although most of the species in this family are highly resistant to the rust. In a severely damaged Scots pine stand in northern Finland, C. flaccidum was found to sporulate commonly on Melampyrum sylvaticum and E. stricta, and rarely on Rhinanthus minor. This is the first report of natural sporulation of C. flaccidum on Rhinanthus in its natural habitat.

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).

Genetic structure, diversity, and hybridization in populations of the rare arctic relict Euphrasia hudsoniana (Orobanchaceae) and its invasive congener Euphrasia stricta

Arctic relict populations, which persist in disjunct locations far south of a species’ normal range, are at the frontline of climate change and may be especially susceptible to the negative impacts of climate warming. Further, these relict populations may face increasing contact with, or become outcompeted by, invasive species if the invasive taxa are spreading along with the warming climate. Relict populations are simultaneously of particular conservation importance due to their unique genetic make-up and potential for adaptations to warmer temperatures compared to populations at the core of the species range. In this study, we used genotyping-by-sequencing to study the population genetics of Euphrasia hudsoniana, a polyploid arctic disjunct of conservation concern, at the southern edge of its range along the northwestern shore of Lake Superior. In addition, we examined evidence for hybridization with its invasive congener, E. stricta. Overall, we found clear differentiation between the native and invasive species indicated by nearly all analyses. There was limited evidence for gene flow from the invasive into the native species, but patterns were consistent with more extensive gene flow in the opposite direction. Differentiation among native populations was low, yet two of the five populations fell into a separate, distinct group based on STRUCTURE analyses. Continued genetic monitoring of these populations will help elucidate whether hybridization with invasives is a burgeoning threat for this arctic relict.

Five plant families support natural sporulation of Cronartium ribicola and C. flaccidum in Finland

Natural sporulation of Cronartium ribicola and C. flaccidum were investigated on known and potential alternate hosts growing in three botanical gardens representing different geographic regions in Finland and in some natural habitats next to the northern botanical garden. Uredinia and telia of Cronartium were searched for from over 27,000 leaves collected or checked in the field in 66–96 species representing 16 plant families susceptible to Cronartium. Cronartium ribicola was found on 19 species or cultivars, while C. flaccidum occurred on 17 species. Uredinia and telia of Cronartium ribicola lacked in the southern botanical garden, but they occurred on 5–16 Ribes species or cultivars in the other two botanical gardens. Cronartium ribicola sporulated on one to four Ribes rubrum cultivars, one to three R. uva-crispa cultivars, three to seven R. nigrum cultivars, R. aureum and R. glandulosum in the gardens. Cronartium flaccidum sporulated on five to nine species in the botanical gardens including species of Paeonia, Melampyrum, Loasa, Pedicularis and Vincetoxicum. In natural habitats next to the northern botanical garden, C. flaccidum sporulated also on Melampyrum sylvaticum and Euphrasia stricta var. stricta. Among all the infected species, C. flaccidum sporulated most frequently on Paeonia. For the first time, C. flaccidum was found on E. stricta growing in its natural habitat. Although the frequency of infected leaves under natural inoculum was low for several infected species, the large variety of susceptible species serve as an efficient tool for Cronartium to spread. Based on the amount of natural sporulation in the gardens and their surroundings, both Cronartium rusts are widely distributed and sporulate in different geographic areas in Finland.

Nasa, Nemesia and Euphrasia: new alternate hosts of Cronartium spp.

SummarySusceptibility of 18 alternate host species to Cronartium flaccidum or C. ribicola was tested. Alive test plants were inoculated in the greenhouse and the formation of Cronartium uredinia and telia was followed on the plants for 8 weeks. Cronartium flaccidum formed uredinia and telia on Bartsia alpina and Euphrasia stricta (Orobanchaceae), Nasa triphylla and N. urens (Loasaceae), Nemesia floribunda (Scrophulariaceae), Tropaeolum majus (Tropaeolaceae), Veronica daurica (Plantaginaceae) and Vincetoxicum hirundinaria (Apocynaceae). Single uredinia or telia developed also on N. urens and E. stricta inoculated with C. ribicola. For the first time, Cronartium are reported to sporulate on members of Loasaceae and Scrophulariaceae, N. urens and N. floribunda.

Structural features of flower trichomes in drug eyebright (Euphrasia stricta D. Wolff EX J. F. Lehm.)

<em>Euphrasia stricta </em>D. Wolff ex J. F. Lehm. (Orobanchaceae) is a representative of plants that are widely used in folk medicine, phytomedicine, and homeopathy. The medicinal raw material derived from the drug eyebright is applied primarily in treatment of ophthalmic diseases. The investigations of trichomes in drug eyebright (<em>Euphrasia stricta </em>D. Wolff ex J. F. Lehm) were conducted in 2010–2011. Using light microscopy and scanning electron microscopy, their location and morphological and anatomical features were identified. Three types of non-glandular trichomes were found: short unicellular, long 1–2 celled, and long 2-celled with wall ornamentation. Additionally, 7 types of glandular trichomes were found; these included: unicellular clavate, 2–3-celled clavate, capitate with a unicellular head and a 3-cel- led stalk, capitate with a unicellular head and a 2-celled stalk, capitate with a 2-celled head, conical papillae, and ribbon-like trichomes with wall thickening.

Volatile constituents of Euphrasia stricta

The genus Euphrasia is fairly large with 450 species distributed in both the hemispheres in Europe, Asia, Northern parts of America, mountains of Indonesia to New Zealand, and South America [1]. The Serbian flora recognizes eight species of Euphrasia genus [2]. Euphrasia stricta J. P. Wolff ex J. F. Lehm. (eyebright) has been a part of the traditional folk medicine for centuries and is used for the treatment of various eye problems such as cataracts, conjunctivitis, and red, inflamed, irritated, and sore eyes [3–5]. The literature data on its constituents and their action is limited. The principal compounds in the aerial part are iridoids, phenolic acids, and phenylpropane, and flavonoid glycosides [6–8]. To the best of our knowledge, there is no report found in the literature on the chemical composition of Euphrasia stricta volatile constituents. Aerial parts of Euphrasia stricta were collected during the flowering period, in August 2011, from natural populations of Bojana s Waters, Suva Planina Mountain, Serbia. A voucher specimen, with the accession number 16517, is deposited at the Herbarium of the Department of Botany, Faculty of Biology, University of Belgrade – Herbarium Code BEOU. Oil was obtained from air-dried aerial parts of the plant in 0.02% (w/w) yield by hydrodistillation for 4 h using a Clevenger-type apparatus. The oil analyses were performed simultaneously by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) systems. The GC analysis of the oil was carried out on an HP-5890 II gas chromatograph equipped with a split-splitless injector on an HP-5MS capillary column (30 m 0.25 mm, 0.25 m film thickness) with helium as the carrier gas (1 mL/min) and flame ionization detector (FID). Operating conditions: injector temperature 250 C and interface temperature 280 C, temperature program from 50 C (3 min) to 250 C at a rate of 3 C/min. GC/MS analyses were performed on an Agilent Technologies apparatus, Model GS 6890N, at 70 eV coupled with a mass selective detector MSD 5975C under the same gas-chromatograph conditions. The identification of compounds was based on a comparison of Kovats retention indexes using AMDIS software (ver. 2.64) in combination with a chemometric multivariate resolution method and selective ion analysis (SIA) [9]. The identity of the compounds was confirmed by comparing their data with those from the literature [10], and their mass spectra with the Wiley 275 and NIST/NBS libraries. Relative retention indexes (RRI) were obtained by co-injection a C9–C28 standard mixture of aliphatic hydrocarbons. The results of GC and GC/MS analyses of the investigated oil are summarized in Table 1. Forty-seven compounds were identified, representing 84.0% of the total oil. Fatty acids and their derivatives were found in large quantities. Palmitic acid was detected as the major component, constituting 20.3% of the oil. Other significant compounds were -palmitolactone (11.4%), ethyl linolate (7.6%), 9,12,15-octadecatrien-1-ol, (Z,Z,Z) (6.1%) and phytol (5.2%), while other constituents were in less than 5%.

New alternate hosts for the rustsCronartium ribicolaandCronartium flaccidumin Finland

We explored the potential of the North European flora and some garden plants growing naturally outside Europe to support a reservoir of pine stem rusts. Live plants and detached leaves of 35 species in 16 families (Solanaceae, Verbenaceae, Grossulariaceae, Paeoniaceae, Balsaminaceae, Gentianaceae, Scrophulariaceae, Loasaceae, Tropaeolaceae, Acanthaceae, Myricaceae, Phrymaceae, Plantaginaceae, Orobanchaceae, Apocynaceae, and Fagaceae) were inoculated in the greenhouse and (or) laboratory with aeciospores of Cronartium ribicola J.C. Fisch. and Cronartium flaccidum (Alb. & Schwein) G. Winter in 2010. Cronartium flaccidum produced uredinia and (or) telia in 14 species in nine families, 11 of which represent new alternate hosts in Finland and nine also elsewhere (excluding Nemesia versicolor and Tropaeolum majus L.): Euphrasia stricta D. Wof. ex J.F. Lehm., N. versicolor E. Mey. ex Benth., Nemesia strumosa Benth., Verbena × hybrida Voss., Verbena officinalis L., Veronica longifolia L., Impatiens glandulifera Royle, T. majus, Loasa triphylla Juss., Asclepias incarnata L., and Bartsia alpina L. Cronartium ribicola formed fruitbodies in nine species and cultivars in five families, five of which are new alternate hosts for this species in Finland and also elsewhere: Mentzelia lindleyi Torr. & A. Gray, A. incarnata, B. alpina, L. triphylla, and T. majus. Both species of Cronartium infected four alternate hosts, each in its own family. The alternate host range of each Cronartium was wider than expected and wider than that previously described. In local natural forests, Euphrasia , Veronica , and Bartsia (in northern Finland) are potential hosts that are common and may be able to spread these rusts. The recently established ornamental I. glandulifera could provide the means to spread C. flaccidum to Scots pine ( Pinus sylvestris L.) in southern Finland, and species of Mentzelia may be important for the spread of C. ribicola.

The structure and distribution of glandular trichomes on the stems and leaves of drug eyebright (Euphrasia stricta D. Wolff ex J. F. Lehm.)

<i>Euphrasia stricta</i> is a medicinal plant being one of the ingredients of "Herba Euphrasiae". Many studies have been devoted to the identification of biologically active substances in the herb of eyebright, but much less research has been done on the constitution of glandular structures of this taxon. This paper relates to glandular trichomes located on the stems and leaves of <i>E. stricta</i>. The trichome structure was examined using light and scanning electron microscopy. It was shown that the stems of <i>E. stricta</i> were mainly covered by non-glandular trichomes, whereas glandular trichomes were rarely found on them. However, clusters of short capitate trichomes were found to occur in specific epidermal regions on both surfaces of the leaf blades and bracts. On the adaxial leaf surface, glandular trichomes grew only in the grooves above the vascular bundles, while on the abaxial surface in the depressions located in the expanded part of the teeth. The glandular hairs consisted of 1-2 cells of the stalk and a two-celled head. Trichomes with 3- or 4-celled heads were found sporadically. The glandular trichomes functioned non-synchronously, since they differed in head size and the colour of cell protoplasts. The presence of a light secretion was found on the surface and around the trichomes in both fresh and dry plant material.

Euphrasia liburnica from Romania

In many European countries, the taxonomy and corology of the Euphrasia species, including in Romania, remain unclear even nowadays. As a result of collecting and analyzing a material from the Capatânii Mountains, Beleoaia Peack, material belonging to the Euphrasia genus, we have noticed that it corresponds to a taxon which even now is placed under question in Romania's flora. The analysis of our material according to recent literature has led to the conclusion that the species is part of the E. stricta group, which is recognized by the usually rigid and erect stem and branches. Leaves glabrous to densely hairy, frequently also with short glandular hairs, usually narrowly ovate or elliptical to oblong-lanceolate; floral leaves usually appressed to the flower, with long, very acute to aristate teeth, the basal teeth apically directed. Capsule usually much shorter than calyx, oblong to elliptic-oblong. Within this group, in the 3 rd volume of Flora Europaea, 4 species are included: Euphrasia stricta D. Wolff ex J. F. Lehm. (E. brevipila Burnat et Gremli, E. condensata Jordan, E. tatarica auct., non Fischer ex Sprengel), E. hyperborea Joerg., E. pectinata Ten. (E. tatarica Fischer ex Sprengel) and E. liburnica Wettst. From this whole group, in our country's flora are treated only two species: Euphrasia stricta D. Wolff ex J. F. Lehm. Which includes the subspecies pectinata (Ten.) P. Fourn (E. tatarica Fischer ex Sprengel) and the subspecies brevipila (Burnat et Gremli) Ciocârlan and E. liburnica Wettst. (with a question mark). Among the taxons of the material we collected, it corresponded to Euphrasia liburnica Wettst., thus clarifying the question marks from various works regarding the presence of this taxon in our flora. When determining the taxon we used material we collected ourselves from the above-mentioned research area, which we analyzed according to recent specialized literature. It is recognized by the following characters: 15-25 cm stem, purple leaves, glabrous or with hairs, not glossy when faded; the superior ones and the bracts ± ovate, length maximum two times greater then the width, with close-together dents. The corolla has a length of 4,5- 6,5 mm, and is lilaccoloured. The first flower appears at nodes 5-8. The capsule presents frequent and long ciliums on the edges, shorter or equal to the calyx. The proportion between the length and the width of the capsule is above 2.

Transfer of iridoid glucosides from host plant Galium verum to hemiparasitic Euphrasia stricta

1. Subject and sourceEuphrasia stricta J. F. Lehm. is a small hemiparasitic annual plant growing in dry habitats. The genus Euphrasiahas traditionally been placed in the family Scrophulariaceae, but recently, it has been transferred to Orobanchaceae(Olmstead et al., 2001; APG II, 2003). The plants in the present work were collected on a dry shore meadow inlate September at the peninsula Odden of NW Sealand, Denmark. They were growing in a community with mainlyAchillea millefolium L., Artemisia campestris L. (Asteraceae), Armeria maritima (Miller) Willd. (Plumbaginaceae),Festuca ovina L. (Poaceae), Galium verum L. (Rubiaceae), Plantago lanceolata L. (Plantaginaceae) and SedumacreL. (Saxifragaceae). Avoucher number (IOK-31/2003) has been deposited at the Botanical Museum, The Univer-sity of Copenhagen.2. Previous workSome species of Euphrasia have been chemically investigated (Sticher and Salama, 1981; Salama and Sticher,1983; Kamalyan et al., 1996; Erso¨z et al., 2000, 2002) and the characteristic iridoid glucosides found are aucubin,iridoid aldehydes like plantarenaloside, ixoroside and euphroside, as well as caffeoyl phenylethanoid glycosides(CPGs) like verbascoside.Many species of Galium have been investigated for iridoids (Mitova et al., 2002, and cited references); the genus ischaracterized mainly by asperuloside and its congeners.The interaction and transfer of compounds between host and parasitic plants have been the subject of much dis-cussion (Rank et al., 2004, and cited references), however, not many specific compounds produced by the host planthave been isolated from the parasite with certainty. Published examples are transfer of petroselinic acid from Hederato Orobanche (Lotti and Paradossi, 1987); of pyrrolizidine (from Lolium and Senecio) and quinolizidine (from Faba-ceae genera) alkaloids to Castilleja, Orobanche, Orthocarpus, Pedicularis or Rhinanthus (Wink et al., 1981; Stermitz

Diversity of MAPs in some plant communities of Stara Planina

The high floristic diversity of Stara Planina was the starting base for the research of medicinal and aromatic plants (MAPs) in individual forest and meadow communities. The sites Javor and Prelesje, forest community Fagetum moesiacae montanum B. Jov. 1953, pioneer community of birch Betuletum verrucosae s.l. and meadow community Agrostietum vulgaris (capillaris) Pavlovic, Z. 1955, were researched as follows: soil types, floristic composition and structure of the community, percentage of MAPs, as well as the selection of species which, according to the predetermined criteria can be recommended for further exploitation. The study shows that the soil of the forest communities is eutric brown, and meadow soils are dystric and eutric humus-siliceous. The percentage of MAPs in the floristic structure of the study sites in forest and meadow communities is 32.35%. The following species can be recommended for the collection and utilisation: Hypericum perforatum L., Asperula odorata L., Dryopteris filix-mas (L) Schott. Urtica dioica L., Euphorbia amygdaloides L., Prunella grandiflora L. Tanacetum vulgare L., Achillea millefolium L., Rumex acetosa L., Campanula glomerata L., Stachys officinalis (L) Trevis., Plantago lanceolata W. et K., Potentilla erecta (L) Rauchel, Chamaespartium sagittale (L) P. Gibbs. Cynanchum vincetoxicum (L) Pers., Euphrasia stricta Host., Fagus moesiaca (Matt) Liebl. and Fragaria vesca L.

Genetic structure of Euphrasia stricta on the Baltic island of Gotland, Sweden

Genetic differentiation between and within five varieties of Euphrasia stricta (var. brevipila, var. gotlandica, var. stricta, var. suecica and var. tenuis) on Gotland was investigated, using amplified fragment length polymorphism, AFLP. The varieties are described in the literature by morphology and association to habitat type. We wanted to investigate whether the varieties are locally adapted populations to the typical habitat type for each variety or if they are preadapted to certain habitat types and have colonized Gotland in their present form.A constrained principal coordinate analysis revealed three genetically differentiated subunits within the species. The two early‐flowering varieties suecica and tenuis each formed a distinct group, while the three late‐flowering varieties brevipila, gotlandica and stricta together formed the third group. A phylogenetic tree confirms the partitioning into three groups. Within the group containing the late‐flowering varieties there are populations that pair as each other's closest relatives, but belong to different varieties. These pairs are also geographically adjacent.The phylogenetic tree had a “star‐like” appearance indicating a stronger divergence between populations than between varieties. The same pattern was seen in the partitioning of genetic diversity, with a lower amount of genetic variation occurring between varieties, FST=0.14, than between populations within the varieties, FST ranging from 0.26 to 0.60.In Euphrasia stricta the varieties suecica and tenuis and the group containing the varieties stricta/gotlandica/brevipila are likely to have a phylogeographical history outside Gotland, or an ancient and concealed local origin on the island. Within the group stricta/gotlandica/brevipila local evolutionary events seem to determine the variety identity, probably through local adaptation.

How can we protect rare hemiparasitic plants? Early-flowering taxa ofEuphrasia andRhinanthus on the Baltic island of Gotland

Euphrasia stricta var.suecica, E. stricta var.tenuis, andRhinanthus serotinus subsp.vernalis are three endangered, hemiparasitic annual herbs found in traditionally managed hay meadows on Gotland, Sweden. We have studied — experimentally and in the field — how some features in the present and traditional management cycle affect their fitness. We set up permanent 50 × 50-cm plots in a coastal hay meadow where bothE. stricta var.suecica andRhinanthus are still quite common. The survival, growth and fecundity of cohorts ofEuphrasia andRhinanthus were followed throughout the growing season for three years. The length of the growing season was vital forEuphrasia andRhinanthus performance. In cooler summers, the percentage ofEuphrasia individuals that produced mature seeds was decreased by 20% at the time of mowing. This indicates the need to individually adjust the time of mowing, as was formerly done, to the actual phenological development in order to maintain healthy populations. It is also important to consider the effect of time of mowing on total species richness, asEuphrasia more successfully established in 10 × 10-cm squares with high species richness. Also, the time in spring when hemiparasite growth started was crucial. Cohorts of bothEuphrasia stricta var.suecica andRhinanthus that connected to hosts and started growing early in the season had a strong advantage over later cohorts by having fitness values four to eight times higher. From this we conclude that the traditional practice of spring raking is important for the long-term persistence of these hemiparasites, since raking promotes an earlier onset of both host and hemiparasite growth. Another important issue is the traditional, but nowadays often neglected practice of letting the hay dry in the meadow after mowing. Hay that was left to dry in the meadow contributed significantly moreRhinanthus seed to the meadow than hay that was taken away immediately after mowing. We also found that seedling emergence and subsequent growth ofEuphrasia stricta var.suecica was greatly enhanced by a second hay cut in September. A second cutting mimics some of the positive effects of the traditional practice of aftermath grazing, which is nowadays often abandoned.

Genetic structure in two meadow varieties ofEuphrasia stricta on the Baltic island of Gotland (Sweden) and implications for conservation

Genetic structure in two meadow varieties of Euphrasia stricta on the Baltic island of Gotland (Sweden) and implications for conservation

Tolerance of an annual hemiparasite, Euphrasia stricta agg., to simulated grazing in relation to the host environment

Summary Many annual plants are adapted to man-made habitats, such as grazed and mown meadows, because they are poor competitors and hence confined to relatively open habitats with low vegetation. In order to survive in grazed and mown habitats, they should also have evolved tolerance to apical damage. We studied the tolerance of eyebright (Euphrasia stricta agg.), a hemiparasitic annual, to varying intensities of apical damage (0%, 10% and 50% cutting) in a common garden experiment in two consecutive seasons with Trifolium repens and Festuca rubra as available hosts. The host environment was manipulated by mowing or by leaving the surrounding vegetation intact. Because root hemiparasitic plants poach resources from their host plants, while the hosts are simultaneously also potential competitors for light, mowing of the surrounding vegetation may have both negative (less host resources available) and positive (reduced competition) effects on hemiparasites. In the present study, neighbourhood mowing tended to improve the growth and fruit production of apically damaged eyebright plants. In the first study year, apically damaged (10% cut) plants produced more branches, higher shoot biomass and more fruits compared to intact plants when the surrounding vegetation was mown. No such overcompensation was observed either in an unmown neighbourhood or in the second year. The plants tolerated more extensive damage less well, and all of the 50% cut plants died in the second year in the unmown neighbourhood. The poor survival of these plants was likely to be due to the unfavourable combination of heavy damage, summer drought and competition with the surrounding vegetation. The present study suggests that Euphrasia, and possibly also other annual meadow herbs, may tolerate relatively well minor apical damage, while more extensive damage is likely to adversely affect their performance. The results also support a compensatory continuum in which grazing tolerance varies from undercompensation (damage decreases plant performance) in unfavourable conditions to overcompensation (damage increases plant performance) in favourable growing conditions. While tolerance to apical damage may contribute to the success of these species, they are poor competitors, and their long-term persistence may hence notably depend on the fact that grazing and mowing suppress stronger competitors by maintaining low vegetation.

Le statut des Euphrasia borealis, E. nemorosa et E. stricta dans l'est de l'Amérique du Nord : une analyse numérique

The taxonomic status of Euphrasia borealis, E. nemorosa, and E. stricta in eastern North America has been the subject of considerable controversy. A sample of 184 operational taxonomic units were scored for 58 morphological characters, and the resulting data matrix was subjected to cluster and principal component analyses. Two groups were recognized on the basis of bract and upper cauline leaf characters and designated as E. nemorosa and E. stricta. These two groups were then subjected to several discriminant analyses (stepwise, linear, and canonical) using quantitative data. The results do not support the recognition of E. borealis and E. nemorosa as separate taxa. These plants should be treated as a single species, for which the correct name is E. nemorosa. Euphrasia stricta is, however, morphologically distinct from E. nemorosa. Some geographic differentiation was observed between plants of E. nemorosa from Newfoundland and those from Quebec, but not enough to warrant the recognition of infraspecific taxa. No evidence of hybridization between E. nemorosa and E. stricta was found. Key words: Euphrasia borealis, Euphrasia nemorosa, Euphrasia stricta, numerical analysis, North America, hybridization.