Genista valsecchiae (Leguminosae), a new species from Sardinia

Genista valsecchiae from SW Sardinia is described and illustrated as a species new to science. It is very similar toG. ephedroides and can be distinguished by morphological differences of habit and inflorescence. It typically occurs in the garigue or maquis and is widespread in SW Sardinia.     

Morphology and distribution of trichomes in Italian species ofTeucrium sect.Chamaedrys (Labiatae) — a taxonomical evaluation

Micromorphology and distribution of trichomes (both secretory and not) in different parts of plants of the five Italian species belonging toTeucrium sect.Chamaedrys have been studied. These characters neatly evidence the differences between the taxa considered; of particular interest are the observations concerning the dense coverage of peltate hairs on the abaxial face of the leaves ofT. flavum subsp.glaucum and the characters contributing to a better identification ofT. marum andT. subspinosum. The importance of the calyx indumentum as distinctive taxonomical character of the genusTeucrium is confirmed, stressing at the same time the necessity of completing the observations at micromorphological level.     

Micromorphological and Phytochemical Research on Teucrium scorodonia and Teucrium siculum from the Italian Flora

Micromorphology and distribution of trichomes in different plant parts of Teucrium scorodonia and Teucrium siculum from five populations in Italy are described. The composition of volatile compounds in the same plants has also been studied. The micro-morphological characters of the two taxa differ only in the calyces. T. siculum from the Euganean hills shows a great shape variability in the bracts. As far as the volatile compounds are concerned, this taxon reveals a somewhat special position, particularly for the presence of monoterpenes, which are lacking in T. siculum from Central and Southern Italy.     

Inhibitory effect of Teucrium ramosissimum extracts on aflatoxin B1, benzo[a]pyrene, 4-nitro-o-phenylenediamine and sodium azide induced mutagenicity: Correlation with antioxidant activity

The mutagenic potential of total oligomers flavonoids (TOF), ethyl acetate (EA) and petroleum ether (PE) extracts from aerial parts of Teucrium ramosissimum was assessed using Ames Salmonella tester strains TA98, TA100 and TA1535 with and without metabolic activation (S9). None of the different extracts produced a mutagenic effect. Likewise, the antimutagenicity of the same extracts was tested using the “Ames test”. Our results showed that T. ramosissimum extracts possess antimutagenic activity against all the tested genotoxicants (aflatoxin B₁, benzo[a]pyrene, 4-nitro-o-phenylenediamine and sodium azide) in the Salmonella assay systems used in this study. In addition, all extracts showed important free radical scavenging activity toward the radicals DPPH and ABTS except the PE extract.     

Nutlet sculpturing of selectedTeucrium species (Lamiaceae): A character of taxonomic significance

Nutlet sculpturing of 23Teucrium species belonging to six sections was studied. The nutlets of analysed species were characterized by the presence of the oil glands of various density. SectionTeucrium is well defined by very densely distributed trichomes and oil glands on nutlets. Trichomes on nutlets were absent in all other species, except inT. marum from sect.Chamaedrys. Sect.Polium is a homogeneous group, distinguished from the other sections. There are some similarities of this sect. with sect.Scordium. Species of sect.Chamaedrys are heterogeneous and overlap according to the surface sculpturing characters with the other sections. The significance of nutlet microcharacters as additional taxonomical markers in the infrageneric classification of the genusTeucrium is discussed.     

Anatomy, palynology and nutlet micromorphology of Turkish endemic Teucrium sandrasicum (Lamiaceae)

In this study, the anatomical features of the leaf and stem, besides the pollen and nutlet characteristics of Teucrium sandrasicum are investigated. T. sandrasicum, belonging to sect. Teucrium, is an endemic perennial herb growing on serpentine around Muğla province. The anatomical studies on T. sandrasicum revealed that the stem shares the general characteristics of the Labiatae family. The leaves clearly exhibit xeromorphy due to features such as the distribution of stomata on the lower surface (hipostomatic), the occurrence of guard cells below the epidermis (xeromorphic type), inrolled margins, thick cuticle layer, thick outer epidermal cell wall, a high density of trichomes and thick palisade layer of the mesophyll. The anatomical studies showed that the upper epidermal cells of the leaf include many spherocrystals. The pollen grains are prolate, medium in size, 3-colpate with verrucate ornamentation. The nutlets are ellipsoid with a reticulate-verrucate surface. The results have proven that T. sandrasicum is different from the other species of the sect. Teucrium because of the branched trichomes on the stem and the lack of eglandular trichomes on the nutlets.     

Teucrium francoi M. Seq., Capelo, J.C. Costa & R. Jardim, a new species of Teucrium gr. scorodonia (Lamiceae) from Madeira

The species formerly recognized as Teucrium scorodonia in Madeira is here described as new: Teucrium francoi M. Seq., Capelo, J.C. Costa & R. Jardim. Morphologically close to species of Teucrium gr. scorodonia [ T. scorodonia L., T. pseudoscorodonia Desf., T. siculum (Raf.) Guss. and T. kotschyanum Poech], it exhibits, nonetheless, some distinct diagnostic characters. The indumentum density and type of hairs of T. francoi are clearly distinct from those of related species, as are the shape and dimensions of the leaves and bracts, calyx, and corolla, which are all taken as taxonomically significant diagnostic features. A diagnosis and a distribution map are presented for this new species. Morphology, ecology, biogeography, and conservation issues are discussed. Teucrium francoi , which is an endemic from Madeira (Portugal), is to be found mostly in the scope of the association Teucrio francoi–Origanetum virentis J.C. Costa, Capelo, Jardim, Sequeira, Lousã & Rivas-Martínez, but also occurs in somewhat humid habitats, such as open stands of Rosa mandonii Déségl. associated with small streams.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 639–647.     

Morpho-anatomical differentiation of the balkan populations of the species Teucrium flavum L. (Lamiaceae)

Ecological plasticity, i.e., inter-population differentiation of the species Teucrium flavum was analyzed on the basis of morpho-anatomical variability of its five populations from the maquis (Cisto-Ericetea and Cisto-Micromerietea), rocky grounds (Festuco-Brometea) and rocky crevices (Asplenietea rupestris) in the Eumediterranean and sub-Mediterranean region. Univariate statistic analysis included 22 quantitative characters related to the leaf and stem anatomy and morphology. In order to establish the variability and significance of morpho-anatomical differentiation, principal component analyses (PCA), multivariate analyses of variances (MANOVA), discriminant components analysis (DCA) and clustering, according to the UPMGA method based on Mahalanobius’ distances, have been done.The morpho-anatomical analysis of plants from the five distant populations confirmed that the species T. flavum belongs to malacophyllous xeromorphic species. It was established that the plants from all the five populations analyzed are distinguished by stable conservative xeromorphic characteristics. There is a difference between the pronounced xeromorphic plants belonging to Eumediterranean populations and the subxeromorphic sub-Mediterranean ones.     

Teucrium scabrum (Lamiaceae), a new species from Thailand

Summary   Teucrium scabrum (Lamiaceae), a new species from the western part of Thailand, related to T. quadrifarium Buch.-Ham. and T. viscidum Blume is described and illustrated, and a distribution map is provided.     

Labiatae Novae Iranicae,series tertia

Six new species are described:Teucrium chasmophyticum related toT. paederotoides from Northern Syria;Stachys subaphylla from North East Iran, the most xeromorphic representative of Sect.Ambleia; St. veroniciformis andSt. kermanshahensis, closely related to each other but rather isolated from the remainder of sect.Fragilicaulis; St. nephrophylla, still another member of the same section centred in West Iran, North Iraq and South East Turkey, related toSt. glechomifolia; andNepeta allotria from the Elburs mountains in North Iran, of isolated systematic position.

Florae Iranicae praecursores 10–15.     

Comparative study of genotoxicity and antimutagenicity of methanolic extracts from Teucrium chamaedrys and Teucrium montanum in human lymphocytes using micronucleus assay

Since Teucrium chamaedrys and Teucrium montanum are the most popular plants used in the treatment of many diseases, we evaluated genotoxic potential of their methanolic extracts on cultured human peripheral blood lymphocytes (PBLs) using cytokinesis-block micronucleus (MN) assay. Cultures were treated with four concentrations of both plants (125, 250, 500 and 1,000 μg/ml), both separately and in combination with mitomycin C (MMC). The results revealed that extract of T. chamaedrys administered at the tested concentrations did not significantly affect the mean MN frequency in comparison to untreated cells. Methanolic extract of T. montanum increased the mean MN frequency in PBL at the tested concentrations, but significantly only at the concentration of 1,000 μg/ml. In all tested concentrations, the extract of T. chamaedrys significantly reduced the MMC-induced MN frequency, in a dose dependent manner (r = − 0.687, p < 0.01). The extract of T. montanum decreased the MMC-induced MN frequency at the tested concentrations, but statistically only at 125 μg/ml. Both extracts administered alone did not significantly affect the nuclear division index (NDI) at the tested concentrations. In the combined treatments with MMC, the extract obtained from T. chamaedrys in the concentrations of 500 and 1,000 μg/ml significantly decreased NDI values in comparison to MMC-treated cells alone, while the extract of T. montanum significantly decreased NDI at all tested concentrations. Both extracts nonsignificantly decreased NDI at all tested concentrations in comparison to untreated cells. Our results suggest the important function of T. chamaedrys extract in cancer therapy, this methanolic extract may prevent genotoxic effects of chemotherapy in PBLs.     

Structure elucidation and hepatotoxicity evaluation against HepG2 human cells of neo-clerodane diterpenes from Teucrium polium L

Seven neo-clerodanes (teupolins VI–XII) and eleven known compounds were isolated and characterized from leaf extracts of Teucrium polium L., a medicinal plant used in traditional and herbal medicine for its hypolipidemic, hypoglycemic, antioxidant and antiproliferative properties. The structures of these compounds were elucidated by 1D (¹H, ¹³C and DEPT) and 2D (COSY, TOCSY, HSQC, HMBC) NMR experiments and by mass spectrometry analysis. The complete stereostructure of each compound was defined with a NOESY experiment. Because the overexploitation of herbal remedies containing T. polium extracts has resulted in several cases of hepatitis, the hepatotoxic activity of pure metabolites against the human hepatoblastoma cancer cell line HepG2 was assessed by the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) test. All of the compounds showed low toxicity values at the highest concentration tested (200 μM).     

Potential allelopathic effect of neo-clerodane diterpenes from Teucrium chamaedrys (L.) on stenomediterranean and weed cosmopolitan species

The allelopathic effects of neo-clerodane diterpenes, isolated from Teucrium chamaedrys (L.), have been evaluated on the seed germination and seedling growth of four coexisting Mediterranean species (Dactylis hispanica, Petrorhagia velutina, Phleum subulatum and Petrorhagia saxifraga) and two cosmopolitan weeds (Amaranthus retroflexus and Avena fatua). All of the structures have been elucidated on the basis of their spectroscopic features. The bioassays data, analyzed by principal component analysis, showed more negative effects on weeds respect to coexisting species. Moreover D. hispanica, P. velutina, P. subulatum showed both stimulating or inhibiting effects depending on the type of metabolite and the concentration used in the test.     

A morphological,caryological and morphometrical analysis of Teucrium euganeum Vis. and its allies

The aim of the present study is to clarify the taxonomic position of Teucrium euganeum Vis. vis à vis T.siculum (Rafin.) Guss. and T.scorodonia L. The study is based on an analysis of macro- and micro-morphological characters, type, and distribution of trichomes in different parts of the plant, chromosome counts, and a statistical analysis of such morphometric data. The results of the study allow one to consider the populations of the Euganean Hills (Padua, north-eastern Italy) as a sub-species of T.siculum, and, therefore, a new combination is proposed: Teucrium siculum (Rafin.) Guss. subsp. euganeum (Vis.) Tornadore, comb. et stat.nov.     

Biological activities of Teucrium flavum L., Teucrium fruticans L., and Teucrium siculum rafin crude extracts

The genus Teucrium (Lamiaceae) includes 300 species widespread all around the world, which are perennial herbs or shrubs commonly, named germanders. In Italy, Teucrium flavum L., Teucrium fruticans L., and Teucrium siculum Rafin are mostly present in Liguria, Sicily, and Sardegna. Teucrium species are characterized by mono and sesquiterpene hydrocarbons, flavonoids, fatty acid esters, and essential oils. Many species of this genus show antioxidant, antimicrobial, and antifungal activities, rendering them useful as natural preservative ingredients. In view of the interesting biological properties reported for Teucrium spp., in this study we determined the total phenol and flavonoid content of inflorescence extracts of T. flavum L., T. fruticans L., and T. siculum Rafin. In addition, we investigated the in vitro antioxidant and antibacterial activities of inflorescence extracts against pathogenic bacteria. Obtained results demonstrated that extracts had in vitro antioxidant activity and showed antimicrobial ability against Gram-positive and Gram-negative strains albeit with different effectiveness probably due to the different qualitative/quantitative composition of the extract also suggesting that these extracts might be useful in preventing several diseases in which oxidative stress may represent an important pathogenic mechanism.     

Pollen dimorphism in threeTeucrium species (Lamiaceae)

In the Iberian Peninsula and Balearic Islands pollen dimorphism was found inTeucrium fruticans L.,T. pseudochamaepitys L., andT. rotundifolium Schreber. Generally, this dimorphism shows two sizes of pollen grains, the smaller more or less collapsed. The percentage of pollen viability is calculated. Differences in size between viable and nonviable pollen grains are similar, being about 40% inT. fruticans andT. pseudochamaepitys, and about 26% inT. rotundifolium. With regard to pollen viability, the percentage of male sterility is higher inT. fruticans, in which from male sterile (ms) plants, 100% nonviable pollen was obtained from every flower observed. InT. pseudochamaepitys andT. rotundifolium with rare exceptions, the percentage of nonviable pollen does not seem to be significant.     

Genetic variation inOrchis papilionacea (Orchidaceae) from the Central Mediterranean region: Taxonomic inferences at the intraspecific level

The genetic differentiation ofOrchis papilionacea from Italy, Corsica, Sardinia, Sicily, and Greece was analyzed by isozyme studies. No significant differences at any of the 28 loci tested were observed between samples of the putative subspeciespapilionacea from Italy,grandiflora from Sicily andheroica from Greece, or by comparing sympatricpapilionacea-like andgrandiflora-like subsamples from Sardinia and Corsica. The genetic relationships found among the populations studied reflect more their geographic origin than their taxonomic assignment;papilionacea, grandiflora, andheroica are, therefore, at least in the study area, not to be considered as subspecies, but as simple morphs, controlled by few genes (possibly two) with Mendelian inheritance. The genetic divergence observed among the samples studied is very low and consistent with that of geographic populations of a single cohesive gene pool, linked by a high gene flow (Nm = 5.9).     

An efficient in vitro plant regeneration system for the medicinal plant Teucrium stocksianum Boiss.

An efficient and rapid plant regeneration system via direct organogenesis was established for Teucrium stocksianum Boiss. (Lamiaceae), an endangered and valuable medicinal plant. Hypocotyl explants excised from seedlings germinated in vitro were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of kinetin and indoleacetic acid (IAA) to induce shoot formation. Differentiation of multiple shoots was initiated within 3 weeks of culture. Optimal regeneration was achieved on medium containing 3 mg/l kinetin and 0.5 mg/l IAA. This particular medium composition significantly improved the production of multiple shoots directly from hypocotyl explants compared to other combinations of plant growth regulators. Root induction was achieved on half-strength MS medium containing indole-3-butyric acid. Rooted plantlets were successfully acclimatized, with a survival rate of 75–80%. The protocol developed in this study could be used for long-term in vitro conservation and mass propagation of this species.     

Utility of rDNA ITS sequences in the systematics ofTeucrium sectionPolium (Lamiaceae)

A phylogenetic study based on sequence data from the complete internal transcribed spacer region (ITS) of nuclear ribosomal DNA for sect.Polium of the genusTeucrium shows both intersectional congruence and intrasectional incongruence with traditional morphological classifications. We attribute this incongruence largely to problems related to the polyploid complex studied. SectionPolium includes many poorly differentiated taxa of probable recent origin through hybridization followed by polyploidization. Both on the basis of parsimony and distance (Neighbor-Joining method) analyses,T. dunense andT. thymifolium are the species that diverge most from the sampled taxa. However, unlikeT. thymifolium, the morphology ofT. dunense is not much differentiated in relation to the other taxa. Both species are, nonetheless, the only sampled species to occupy isolated, exclusive environments and which may have undergone rapid evolution by a bottleneck effect.Teucrium dunense is found only on dunes along the Spanish and French coasts andT. thymifolium, a chasmophytic species with limited endemism, is found solely on limestone and dolomite cliffs in the low mountains in south-eastern Spain. A hypothesis is presented to explain the discrepancy between the observed comparatively large amount of ITS sequence divergence and the low morphological differentiation inT. dunense.