A palynological study of the genus Mentha L. (Lamiaceae)

The pollen morphology and exine structure of 10 Mentha L . species were investigated using light microscopy and scanning electron microscopy. The pollen grains of all 11 species were hexazonocolpate with granular membranes and a circular amb, varying in shape from prolate-spheroidal to suboblate. Different colpus shapes were recognized in M . ×  dumetorum . The exine was bireticulate in section Pulegium , and reticulate in section Menthae . A correlation was found between pollen size and chromosome number. The results indicate that the pollen characters of the genus Mentha are valuable for taxonomic applications and may be useful for classification.  © 2008 Uludag University. Journal compilation © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 141–154.     

Infrasectional systematics of the genus Sideritis L. section Sideritis (Lamiaceae)

RIVERA NUÑEZ, D., OBON DE CASTRO, C., TOMAS-LORENTE, F., FERRERES, F. & TOMAS-BARBERAN, F. A., 1990. Infrasectional systematics of the genus Sideritis L. section Sideritis (Lamiaceae). A new taxonomic division of the section Sideritis is proposed on the basis of morphological, cytological and chemical characters. The following subsections art-recognized: Grandiflora, Ovata, Camarae, Linearifolia, Gymnocarpae, Stachydioides, Lacaitae, Hirsuta, Chamaedryfolia, Arborescens, Flavovirens, Leucantha, Angustifolia, Serrata and Scordioides . Possible evolutionary pathways are discussed.     

Nutlet micromorphology of Iranian Nepeta (Lamiaceae) species

To evaluate nutlets characteristics for systematic relationships, a comprehensive morphological and micro‐morphological study of the nutlets of 16 Iranian taxa of Nepeta (Lamiaceae) was conducted using scanning electron microscopy (SEM). Differences in surface ornamentation, size, shape and color were observed between the species. The studied taxa were categorized in two basic types based on surface ornamentation: non‐sculptured (smooth‐type) and sculptured nutlets. The non‐sculptured nutlets type could be further divided into four sub‐types, including smooth, granulate, undulate‐cellular and reticulate. In the sculptured nutlets, three subtypes of tuberculate, tuberculate‐cellular and verrucate were recognized. The shape of nutlets were described as oblong, ovoid‐oblong, oblong‐linear, to elliptic‐oblong and their size range are 1.2–2.0 mm in length and 0.5–2.0 mm in width. Based on micrographs, the areole form and location were defined as bi‐lobed, straight, basal, sub‐basal or lateral. Nutlet micromorphological characteristics such as surface ornamentation can be useful for classification and identification of e.g. medicinal species of Nepeta in Iran.     

A chemosystematic study of the genus Gomphostemma and related genera (Lamiaceae)

Species in the genera Gomphostemma, Chelonopsis and Bostrychanthera were systematically studied with reference to their flavonoid and phenolic acid compounds in order to investigate whether the profiles of these compounds would support a classification of the genus and related genera based on morphological characters. Thirty-five flavonoid glycosides, eight phenolic acids and derivatives were identified by LC-UV-MS/MS analysis of aqueous 80% MeOH extracts on the basis of their UV and mass spectra, retention times and comparison with in-house library. The occurrence of individual compounds was not particularly informative in Gomphostemma, although the overall chemical profile supported G. subgen. Pogosiphon and vicenin-2 was a characteristic component of Gomphostemma leptodon and Gomphostemma curtisii. In contrast, the flavonoids and phenolic acids of Chelonopsis were informative at infrageneric level. Glycosides of 6-substituted flavones were well represented in Ch. subgen. Aequidens, including Ch. forrestii, Ch. rosea, Ch. odontochila, Ch. lichiangensis and C. giraldii. A dicaffeoylquinic acid was produced in Ch. subgen. Chelonopsis, (for example, in Ch. longipes and Ch. Moschata), but absent from Ch. subgen. Aequidens. The same dicaffeoylquinic acid was also found in the genus Bostrychanthera and suggests a close relationship with Ch. subgen. Chelonopsis, in agreement with a recent DNA based phylogeny. There is correlation between trichome type and phenolic acid compound distribution in Chelonopsis, but this is not observed in Gomphostemma.     

Diversity,phytochemical and medicinal potential of the genus Ocimum L. (Lamiaceae)

Phytochemistry Reviews - Ocimum, commonly known as Tulsi, is a huge genus within family Lamiaceae, comprising about 64 species of annual to perennial aromatic medicinal herbs with a long history of...     

Pollen morphology of the genus Salvia L. (Lamiaceae) in Turkey

Pollen grains of 30 taxa of the genus Salvia, belonging to sections Salvia, Horminum, Drymosphace, Plethiosphace and Hemisphace from Turkey were examined by light (LM) and scanning electron microscopy (SEM). Detailed pollen morphological characteristics are provided for these taxa. Among the studied taxa, S. verticillata subsp. verticillata from sect. Hemisphace has the smallest pollen grains, and S. pachystachys from sect. Salvia possesses the largest ones. The basic shape of the pollen grains in most taxa is suboblate, oblate-spheroidal or prolate-spheroidal. However subprolate pollen grains are recorded for S. macrochlamys from sect. Salvia. The grains are hexacolpate in all taxa, but in S. recognita from sect. Salvia also octacolpate pollen was found. Three distinct exine sculpturing types exist, reticulate-perforate (the common type), reticulate-granulate and bireticulate. The reticulate-perforate and bireticulate sculpturing patterns can be divided into subtypes based on the number of perforations and the number of secondary lumina in each primary lumen. Pollen morphological characteristics of the taxa studied are compared and discussed on the basis of taxonomical concepts. In some cases, these characters are useful in distinguishing the sections. For instance, the presence of 1-2 large central secondary lumina per primary lumen is a significant character of sect. Horminum separating it from the other sections. As well, the presence of holes on colpus membrane ornamentation can be used as a diagnostic taxonomic character for sectional division between sect. Hemisphace and others. S. ballsiana from sect. Salvia is clearly distinct from the other taxa examined by its unique pollen morphology. Further, for several macromorphologically similar taxa pollen structures provide additional evidence to delimite them from each other.     

Notes on the genus Erythrochlamys (Lamiaceae)

A new species of the genus Erythrochlamys is described: E. frulicosa from Somalia and Ethiopia. An interesting variation in E, leucosphaera is also discussed.     

Polymorphisms for asymmetric reciprocal translocations in two species of the genus Sideritis L. (Lamiaceae)

Meiotic and karyotypic analyses of six populations of two closely related species belonging to the section Eusideritis of the genus Sideritis (five of S. saetabensis and one of S. tragoriganum) (Lamiaceae), revealed polymorphisms for asymmetric reciprocal translocations. Two populations of S. saetabensis (S-046 and S-089) and the population of S. tragoriganum (S-056) contained heterozygotes and standard homozygotes. No homozygotes for the rearrangement (dicentric) were found. The meiotic behavior of the heterozygotes showed great stability of the dicentric chromosomes in both species due to strict control of meiosis at three levels: (1) chiasma formation, (2) multivalent coorientation at metaphase I, (3) dicentric chromatid separation at anaphase II. During mitosis there may also be strict control of dicentric chromatid separation through 100% parallel separation without interlocking. This stable polymorphism for asymmetric reciprocal translocations is a unique phenomenon that seems to be maintained by over-dominance, thus being a special case of linkage disequilibrium. We give two alternative hypotheses to explain the origin of these polymorphisms and discuss their evolutionary significance.     

Repellent activity of Nepeta grandiflora and Nepeta clarkei (Lamiaceae) against the cereal aphid,Sitobion avenae (Homoptera: Aphididae)

Nepeta spp. (Lamiaceae) contain principally the nepetalactone isomers (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone, which are also known to comprise aphid sex pheromones and aphid parasitoid attractants. Previous studies have shown that Nepeta cataria can be grown as a non-food crop for the commercial-scale production of (4aS,7S,7aR)-nepetalactone in high purity, thus removing requirement for highly demanding stereocontrolled synthesis. Furthermore, previous literature reports have suggested that Nepeta spp., other than the widely studied N. cataria, can produce a diverse range of natural products other than nepetalactones, including high value sesquiterpenes. Thus, with the aim of identifying alternative Nepeta spp. for production of high value semiochemicals, the essential oils of two readily available species, Nepeta grandiflora and N. clarkei, were collected by steam distillation and analysed using high resolution gas chromatography (GC) and coupled GC–mass spectrometry (GC–MS). Analysis of the oils surprisingly revealed a very low nepetalactone content, but instead the presence of predominantly sesquiterpene compounds, and, for N. clarkei, the major component, geranyl acetate. Amongst the compounds identified in both oils was (S)-germacrene d, a previously reported potent arthropod repellent. To determine the potential crop protection value of these essential oils, the repellent activity of the oils was assessed using a four-way olfactometer assay, with both oils showing strong repellent effects. These findings illustrate that members of the Nepeta genus possess a diverse range of high value secondary metabolites, and also highlight their potential to be developed as renewable feedstocks for the production of repellents for use economically important crop pests, as well as for the production of sex pheromones and natural enemy attractants.     

A systematic revision of the genus Teucrium (Lamiaceae) in Egypt

A critical taxonomic revision of the genus Teucrium (Lamiaceae) in Egypt is presented. It reveals the presence of five species, including two subspecies and four varieties. Two new nomenclatural combinations are proposed: Teucrium jordanicum and T. jordanicum var. sinaicum. The latter in addition to T. polium subsp. capitatum are added for the first time to the flora of the country. A key, annotated enumeration of species and notes on the distribution of the species are also provided.     

唇形科独一味属和五种糙苏属植物的核形态研究

首次报道了唇形科Lamiaceae独一味属Lamiophlomis和五种糙苏属Phlomis植物的染色体数目和核型。它们的间期核均属球状前染色体型,有丝分裂前期染色体均为中间型。中期染色体核型公式如下:独一味L.rotata,2n=2x=22=18m 4sm;糙苏P.umbrosa,2n=2x=22=22m;裂萼糙苏P.ruptilis,2n=2x=22=22m;假秦艽P.betonicoides,2n=2x=22=22m;黑花糙苏P.melanantha,2n=2x=22=22m(2sat);糙毛糙苏P.strigosa,2n=6x=66=60m 6sm;染色体基数均为x=11。这表明独一味与糙苏属的糙苏组sect.Phlomoides植物具有相同的染色体基数,反映出两者较为密切的系统演化关系,推断独一味很可能是糙苏属的一个种。     

The genus Callicarpa (Lamiaceae) on Borneo

The Bornean species of Callicarpa (Lamiaceae) are revised. Twenty three species are recognized: of these, four are described as new ( C. argentii , C. coriacea , C. subaequalis and C. teneriflora ) and two are raised to species level from variety ( C. endertii and C. hispida ). All 23 species described are assessed for World Conservation Union (IUCN) conservation status. Distribution maps and an identification key are provided. The historic confusion between the genera Geunsia and Callicarpa is discussed. Geunsia is included as a synonym of Callicarpa based on the examination of morphological characters and molecular data. Geunsia is suggested to be nested within Callicarpa based on phylogenetic analyses of nuclear ribosomal internal transcribed spacer (nrITS), partial matK and trnD‐T sequences of 30 taxa using maximum parsimony. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 416–455.