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The genus Phlomis is represented in the island of Crete (Greece, Eastern Mediterranean) by three species Phlomis cretica C. Presl., Phlomis fruticosa L., the island endemic Phlomis lanata Willd. and three hybrids Phlomis x cytherea Rech.f. ( P. cretica x P. fruticosa ), Phlomis x commixta Rech.f. ( P. cretica x P. lanata ) and Phlomis x sieberi Vierh. ( P. fruticosa x P. lanata ). This work describes (a) the profile of hybrids and parental species concerning their volatile compounds, (b) the suitability of ribosomal nuclear (ITS region), chloroplast ( trn H -psb A), and AFLP markers to identify hybrids and (c) their competence to characterize the different chemotypes of both hybrids and their parental species. The cluster analysis and PCA constructed from chemical data (volatile oils) suggest that there are three groups of taxa. Group IA includes P. cretica and P. fruticosa , group IB includes P. x cytherea , whereas group II consists of P. x commixta , P. x sieberi and P. lanata . Volatile compounds detected only in the hybrids P. x sieberi and P. x commixta correspond to the 3% of the total compounds, value that is much higher in P. x cytherea (21%). Neighbor-joining, statistical parsimony analysis and the observations drawn from ribotypes spectrum of ITS markers divided Phlomis species in two groups, P. lanata and the complex P. cretica / P. fruticosa . In contrast to the ITS region, the plastid DNA marker follows a geographically related pattern. Neighbor-Net, PCA and Bayesian assignment analysis performed for AFLP markers separated the genotypes into three groups corresponding to populations of P. cretica , P. fruticosa , and P. lanata , respectively, while populations of P. x commixta , P. x cytherea , and P. x sieberi presented admixed ancestry. Most of the P. x cytherea samples were identified as F1 hybrids by Bayesian assignment test, while those of P. x commixta and P. x sieberi were identified as F2 hybrids. Overall, high chemical differentiation is revealed in one of the three hybrids, which is likely related with niche variation. Moreover, molecular markers show potential to identify Phlomis taxa. [ABSTRACT FROM AUTHOR]

Abstract: Origanum vulgare L. subsp. hirtum (Link) Ietsw. is a polymorphic taxon with respect to essential oil production and glandular trichome density. Here it is examined whether the natural populations that are indigenous in continental Greece may be considered as different ecotypes (i.e. populations with different genetic variation) and whether evidence regarding a fitness cost from essential oil production could be obtained. Samples from 30 different natural populations, differing in climatic conditions, were collected across continental Greece in 1998–2000 and were studied for essential oil production and glandular trichome density. Additionally, individual plants, derived from propagated rhizomes, originated from the natural populations, were transplanted in pots in two gardens that varied in terms of mean temperature and aridity. In these experimental populations, the above-ground phytomass and ratio of leaves and inflorescences to above-ground phytomass were additionally measured. The main findings of the study were (a) a strong positive correlation between essential oil concentration and glandular trichome density, (b) a high positive correlation between natural and experimental populations in essential oil concentration (or glandular trichome density), (c) a negative correlation between essential oil concentration and phytomass and (d) a positive relationship between the essential oil concentration and the factors thermal status and summer drought of the location of origin. Results suggest that the examined populations of O. vulgare subsp. hirtum are different ecotypes, the production of essential oils has a cost to plant growth and that the prime target of selection, by producing these oils, is to increase the resistance to drought and heat stresses. [Copyright &y& Elsevier]

Abstract: The study of essential oils obtained from Coridothymus capitatus and Satureja thymbra collected from different natural habitat types of 11 NATURA 2000 sites scattered all over Crete has shown that they are characterized either by a high amount of carvacrol (up to 75.7%) or thymol (up to 65.6%) or by a more or less equal amount of the two phenols. The results of a discriminant analysis with predefined groups the natural habitat types wherefrom the plants were collected have shown that the oils of both species collected from the dry dwarf-shrub formations of the lowland have a high carvacrol content whereas those collected from the more mesic timber or highland formations have a high thymol content. Furthermore, the results of this study introduce the use of natural habitat unit as a tool for the assessment of essential oil variation. [Copyright &y& Elsevier]

Abstract This is the first account of the essential oils of wild Greek plants of Thymbra spicata , an East Mediterranean species used as a culinary herb and herbal tea. In particular, the yield and composition of the essential oil of Th. spicata from Chios Island is recorded and compared between two seasons. Considering that Chios provides the westernmost studied material of Th. spicata , the geographical variation in the main essential oil compounds in the total natural range of the species in relation to its systematics is also discussed. The essential oil yield of the Chios plants ranged from 2.4 to 4.8 mL 100 g−1 dry weight (aerial parts without stems). Carvacrol (responsible for the “oregano” scent) was dominant in considerably high amounts (67.5%–88.3% of the total oil) and without significant seasonal differences. Other main compounds were p -cymene (0.7%–17.4%), γ-terpinene (0.1%–6.9%) and caryophyllene oxide (0.9%–2.5%). Τhymol (responsible for the “thyme” scent) was always very low (0.3%–0.7%). Throughout the East Mediterranean, carvacrol is dominantly the major essential oil compound of Th. spicata. p -Cymene, γ-terpinene and other, more minor, compounds contribute to local differences in the species' essential oils in its total range. The thymol-chemotype is scarce throughout the species' range and not related to the local Turkish subspecies intricata as previously suggested. Despite the closer taxonomic affinities with the genus Thymus and the thyme-related vernacular names attributed to Th. spicata , this species can be characterized as an “oregano” with regard to its essential oil composition and herbal use. Highlights • The essential oil yield of Thymbra spicata from Chios Island is 2.4%–4.8%. • Carvacrol dominates the essential oils of Th. spicata in Chios up to c. 88%. • The carvacrol-chemotype (“oregano scent”) dominates in the species' total range. • The thymol-chemotype (“thyme” scent) is scarce in the species' total range. • The thymol-chemotype is not related to subsp. intricata. [ABSTRACT FROM AUTHOR]

Oregano herbs have wide culinary uses and industrial applications due to the high antioxidant and other activity of their main essential oil compound, carvacrol. Among the oregano herbs, Origanum onites (known as “Turkish oregano”, “Island oregano” or “Cretan oregano”) is a narrowly distributed East Mediterranean species occurring mainly in Turkey and Greece, which comprises one of the major herbs of the oregano trade worldwide. We examine the essential oils of O. onites plants collected from 42 localities scattered along the total range of the species on Chios, a Greek island bordering with the Turkish mainland. We focus on the essential oil yield and five oil compounds, namely carvacrol, thymol, borneol and the biosynthetic precursors of the first two, i.e., p -cymene and γ-terpinene, in relation to the habitat type, geological substrate, altitude, bioclimatic area and geographical location, where the collected plants were growing on the island. We also discuss our results in relation to the essential oil based distinction between O. onites and another commercially important East Mediterranean oregano herb, namely O riganum vulgare subsp. hirtum (known as “Greek oregano”). The determined essential oil yield (3.0–7.0 mL/100 g of dry leaves and inflorescences) and carvacrol content (69.0–92.6%) of the examined O. onites plants from Chios are among the highest reported for this species. The essential oil yield and the content of the five compounds were not found to vary in relation to the different environmental factors examined. These findings let us conclude that the wild oregano of Chios is a valuable natural resource with a high potential for industrial use, due to its high essential oil yield and carvacrol content, that are not influenced by environmental conditions. Moreover, based on our results and recent literature we conclude that O. onites can be distinguished from O. vulgare subsp. hirtum based on the relative content of carvacrol, thymol, borneol and p -cymene – primarily borneol – in the two taxa’s essential oils, a useful means of distinction when the botanical identity of fragmented commercial oregano products is questioned. [ABSTRACT FROM AUTHOR]

Abstract: Satureja pilosa Velen. subsp. origanita Dardioti & Kokkini, is a recently described endemic taxon of NE Greece (Thrace). Its epithet reflects the prominent odor of the plants, due to which it is used by the local people as an “oregano” herb. However, the study of 19 populations scattered along the taxon’s range, revealed that the plants are characterized by a variety of odors. In particular plants from 10 populations, having essential oils rich in carvacrol (up to 62.3% of the total oil), emitted an “oregano” odor, while plants from seven populations, with oils rich in p-cymene (up to 49.8%) and/or thymol (up to 48.1%) had a “thyme” odor; the plants from the other two populations, with linalool-rich oils (59.2 and 82.7%) had a prominent “lavender” odor. A discriminant analysis with pre-defined groups the bioclimatic zone wherefrom the plants were collected has shown that the essential oil content and the amount of carvacrol gradually decrease from the Mesomediterranean to the Temperate Axeric bioclimates, while the amounts of p-cymene, thymol and linalool, increase. Our results, supported by similar findings concerning East Mediterranean taxa traded as “oregano”, have shown that in order to characterize a herb as “true oregano”, the plant odor, reflecting the oil composition, as well as the collection areas of the plants should be taken into account. [Copyright &y& Elsevier]

Abstract: The herbs of the “mint” group traded in the herbal market of Thessaloniki include eight taxa, members of two genera, Acinos (two species) and Mentha (four species and two hybrids). The essential oil content of 72 samples examined ranged from traces up to 1.69ml/100g of dry weight. Besides three almost scentless samples, the different “mints” are distinguished according to their prominent smell differences, i.e. samples with a pungent, musty and sweet type of smell. As a result, the commercial names attributed to them correspond to a particular type of smell and not to a particular taxon. A number of 29 medicinal uses were recorded in total. In most cases uses were not associated with particular taxa but were rather determined by plant smells. A literature survey has shown that the “mints” traded in Thessaloniki are also used as herbal medicines all over the Mediterranean area, with 67 different therapeutic uses. Among them the 22 uses, already mentioned by Dioscurides, show that the utilization of “mints” as herbal medicines in the Mediterranean countries has a long tradition. [Copyright &y& Elsevier]