02967nas a2200205   4500008004100000245010000041210006900141300001400210490000800224520235900232653001702591653001902608653001102627653001602638100001702654700001402671700001702685700001202702856004702714       2012                        eng d00aFlower morphology, nectar traits and pollinators of Cerinthe major (Boraginaceae-Lithospermeae)0 aFlower morphology nectar traits and pollinators of Cerinthe majo  a186–1960 v2073 a<p>In April and May 2010, a natural population of Cerinthe major (Boraginaceae-Lithospermeae) was investigated with regard to: floral morphology, phenology, sexual receptivity during anthesis, the production of nectar and its sugar and amino acid content. The pollinator array of this species was also investigated. Cerinthe major has showy, pentamerous, hermaphroditic flowers with a deep yellow corolla tube arranged on numerous scorpioid inflorescences. Nectar and pollen are the main floral rewards for pollinators. The arrangement of stamens limits access to nectar and promotes pollen loading onto pollinator bodies as they force their way towards the source of nectar. By limiting the direct exposure of nectar to the environment, the corolla tube and the arrangement of anther filaments seemingly protect nectar from evaporation resulting from high temperatures and low relative humidity during flower anthesis. The green, annular nectary located at the base of the ovary lobes is composed of a very thin epidermis enclosing a dense mass of parenchyma. The epidermis lacks stomata, and the thin cuticle has an irregular surface. The parenchyma cells do not store starch during the pre-secretory stage, suggesting that immediate photosynthesis is the most likely source of nectar carbohydrates. Generally, anthesis lasts 4&ndash;5 days; the gynoecium becomes fully receptive on the second day and this is synchronous with anther dehiscence. Since nectar production begins during the bud stage, a substantial volume is available for flower visitors at anthesis. Nectar production decreases drastically in senescent flowers and, if not consumed, the nectar can be re-absorbed. Analysis of sugars revealed a sucrose-dominant nectar (sucrose = 93.18 &plusmn; 1.35%). Proline, GABA, taurine, leucine, citrulline and alanine were the main amino acids present and are probably implicated in pollinator flight performance. The bees Bombus hortorum, Anthophora sp. and Eucera sp. were constant and frequent visitors of C. major flowers. Moreover, the manner in which they interacted with the flower in order to obtain nectar and pollen loads was sufficient evidence for their role as pollinators. Their different foraging behaviours suggest that each species may promote differences in pollen flow both within and among individuals of the population.</p>
10aBoraginaceae10aCerinthe major10anectar10apollinators1 aNocentini, D1 aPacini, E1 aGuarnieri, M1 aNepi, M  uhttps://boraginales.myspecies.info/node/2901980nas a2200169   4500008004100000245012000041210006900161300001400230490000800244520140800252100002301660700001901683700002301702700002001725700001801745856004701763       2013                        eng d00aIntrapopulation heterogeneity in floral nectar attributes and foraging insects of an ecotonal Mediterranean species0 aIntrapopulation heterogeneity in floral nectar attributes and fo  a799–8090 v2143 aA population of Buglossoides purpurocaerulea (L.) I.M. Johnst. (Boraginaceae–Lithospermeae) located in Lecceto (Siena Province, Tuscany, central Italy) has been studied to compare floral nectar attributes and forager species between sun-exposed and shaded plants. Flower anthesis and maturity of sexual organs were also investigated. Average flower anthesis lasted 3–4 days. Stigma receptivity and anther dehiscence occurred on the first day. Nectar production also began on the first day and maximum production occurred on second-third day. Significantly greater volumes and total sugars were recorded in individuals exposed to the sun. Nectar HPLC analysis showed a similar hexose-dominant sugar profile for all the individuals with percentages of sucrose, glucose and fructose around 5, 48 and 47 %, respectively. Protein amino acids represent the 90 % of the overall free amino acids profile. Significant differences between relative percentages of serine and proline were found between sun-exposed and shaded individuals. Empis pennipes and Bombilyus major were the most frequent insect visitors to shaded and sun-exposed individuals, respectively. The hexose dominance of the nectar of B. purpurocaerulea, an exception among the Mediterranean Lithospermeae, may be related to the habitat where this plant generally grows, i.e. the forest-edge, and to pollination mainly performed by dipterans.1 aNocentini, Daniele1 aPacini, Ettore1 aGuarnieri, Massimo1 aMartelli, Diego1 aNepi, Massimo  uhttps://boraginales.myspecies.info/node/28