 This may be attributable to the presence of pharmacologically active ligands of benzodiazepine receptor 

A widespread belief is that the nectar of this species contains mannose, which can be toxic to some bees.This is incorrect; the sight of numerous comatose bees found on the ground at flowering time is rather a result of the paucity of nectar sources in late summer in urban areas.This species, while fragrant in spring, drops buds and pollen during the spring and fall.