Bees require large amounts of pollen for their own reproduction. While several morphological flower traits are known to have evolved to protect plants against excessive pollen harvesting by bees, little is known on how selection to minimize pollen loss acts on the chemical composition of pollen. In this study, we traced the larval development of four solitary bee species, each specialized on a ...

Differences in nutrient-use efficiency have been attributed to differences in leaf habit. It has been suggested that evergreens, with their longer-lived leaves, and therefore longer nutrient retention, are more efficient than deciduous species in their use of nutrients. In tropical trees, however, leaf life span is not always a function of whole-tree deciduousness, leading to the proposal that ...

A complete nomenclatural synopsis is provided for Onosma (Boraginaceae) and the allied genera Maharanga Podonosma, covering each name of new taxa, combination replacement communicated since 1753 till October 2021. All 749 validly published names are listed together with an account formal reasons why 136 additional must be regarded as invalid. Type species indicated or newly designated all infra...

echium amoenum fisch. and c.a. mey. (boraginaceae) is a very popular medicinal plant which is used as a tonic, tranquillizer, diaphoretic, cough remedy, sore throat and pneumonia in iran’s traditional medicine. callus culture of medicinal plants is one of the ways for production of secondary metabolites. in this study, callus culture of e. amoenum and its major secondary metabolite were investi...

Echimidine was isolated from Echium rauwolfii and Echium horridum and identified by MS, 1H- and 13C NMR as a major alkaloid. In addition, structures of 12 minor alkaloids were inferred from GLC and GLC-MS analyses: 7-angeloylretronecine, 7-tigloylretronecine, lycopsamine, 7-acetyllycopsamine, uplandicine, 7-angeloyllycopsamine, 7-tigloyllycopsamine, tigloyl isomer of echimidine, 7-angeloyl-9-(2...