Molecular analysis of orchid pollinaria and pollinaria-remains found on insects

Direct observations of pollinator visits to orchids are often difficult and time consuming, especially in orchids with a deceptive pollination system where seed set is typically pollinator-limited. This lack of direct observations greatly inhibits our understanding of orchid-pollinator relationships and especially the degree of pollinator-specificity. Here we describe a molecular approach to the study of orchid-pollinator relationships based on the analysis of DNA recovered from pollinaria found on insects. The insects were collected from nectar-rich plants flowering near natural orchid populations, or taken from museum collections. Sequence analysis of the nuclear ribosomal ITS region allowed the identification of the orchid species or species-group from which the pollinaria originated. Four out of eight orchid-pollinator relationships established with this approach have not been reported previously, which highlights the value of molecular tools for the study of orchid pollination biology.

Floral Symmetry and Its Role in Plant-Pollinator Systems

Floral symmetry has a relevant status in the study of both pollination biology and animal behavior. In this work, a brief review and classification of symmetry types in flowers is provided as a basis for understanding the role of floral symmetry in pollination phenomena. We focus on insects as a fundamental group of pollinators, and we discuss symmetry from the perspective of insect perception. We conclude that symmetry is a specific cue with a signal value that is perceived by insect pollinators. A simple nervous system, such as that of honeybees, is capable of an extremely flexible and adaptive processing of symmetry. Performances consistent with categorization and concept building may be observed, provided that appropriate learning paradigms are employed. Perfectly symmetrical flowers might signal a high quality and/or quantity of nectar or pollen to pollinators that, in turn, might exert strong selection pressure on symmetric features. However, coadaptation arguments in the strict sense are not adequate because it is impossible to determine whether the insect's capacity to perceive symmetry is younger or older than is the origin of flower symmetry.

Solanaceae as medicinal plants in Israel

In a recent survey, 106 local healers in Israel were interviewed concerning the use of Solanaceae as medicinal plants. The main findings reveal that: (a) only four species (Lycium europeaum, Solanum nigrum, Hyoscyamus aureus, Hyoscyamus albus) are extensively used today; (b) the use of some traditional plants has been almost abandoned (Datura spp., Mandragora autumnalis, Withania somnifera); (c) today all the plants are applied externally, they are rarely used as narcotics; (d) most use of these plants is local, only in a few cases is a uniform use found throughout the whole country, and in all ethnic groups; (e) the extensive distribution of modern, safe narcotics, sedatives and anaesthetics has reduced the use of the Solanaceae for these purposes.

A preliminary classification of the healing potential of medicinal plants, based on a rational analysis of an ethnopharmacological field survey among Bedouins in the Negev desert, Israel

In the course of an ethnopharmacological survey carried out among the Bedouins of the Negev desert, it was noticed that in addition to the use of modern medical services, medicinal plants were also being employed. We deemed it worthwhile, therefore, to investigate the current status of herbal medicine among the Negev Bedouins and to evaluate the relative efficiency of the plants used. To evaluate plant effectiveness by enquiries among patients once treated was found to be difficult and impractical. Hence, each interviewed informant was first requested to volunteer information on the plants and their uses. Next, to avoid the risk of memory failure, a list of 50 commonly used species was read out and the informant was asked to provide information on any that were familiar to him as medicinal herbs. Of 81 plant species mentioned by our 27 informants, 41 were named or recognized by more than 3. These species were arranged in accordance with the percentage of informants suggesting the same medicinal use for a given species as compared with the total number of informants reporting any sort of use for that plant. The obtained ratio was defined as the fidelity level (FL). The rank-order priority (ROP) of the plants was derived from these FL values. The relative popularity level (RPL) of the plants encountered was determined and plants were accordingly designated as "popular" or "unpopular". FL values were further adjusted, according to RPL value. We found that the bark of Phagnalon rupestre is widely used to induce deliberate burns for the healing of various ailments (ROP = 100), while infusion of the shoots of Teucrium polium, or of Artemisia herba-alba is employed to a lesser degree (ROP = 66 and 56, respectively) to relieve stomach disorders. Because the latter two species show fairly high ROP and are seen to be directly curative, they merit further investigation. Additional findings and implications of our ethnopharmacological survey are duly discussed.

Ethnobotanical survey of medicinal plants in northern Israel

An ethnobotanical survey was conducted in Israel on native plants which are known as medicinal plants by different ethnic groups practicing traditional medicine. In this work 43 species are reported, based on quotations and frequency of utilization. Their current medicinal uses, as well as methods of preparation and administration are described and compared with literary evidence.