Pollination and Seed Production of Lavandula angustifolia Mill. (Lamiaceae)

Abstract

Lavandula angustifolia Mill., lavender, is an aromatic plant in the Lamiaceae family. Lavender is an important economic plant that is cultivated throughout the world. Previous studies have shown that the primary pollinators of lavender in Europe and North Africa are bee species, specifically Bombus spp. However, similar studies have not been previously performed in North America. The current study, on cultivated population lavender (grown from seed) in Utah (USA), found a diverse community of bees visiting lavender over a 4-week sequential and successive blooming period. The observed and identified bees were distinguished across 8 genera and 12 species, of which 3 were species not native to North America. The most observed bees were Apis mellifera (88.3%), Bombus fervidus (4.2%), and B. huntii (3.7%). To investigate seed production and viability, lavender plants were either caged off and their access withheld from pollinators, or selectively granted access to various pollinators, to determine (1) if lavender is capable of self-pollination, (2) if pollination increases both the seed production rates and seed viability of lavender, and (3) which bee species are the most efficient pollinators of lavender. The findings from this study demonstrate the ecological interactions between pollinators both native and non-native to North America on lavender, a plant native to the Mediterranean region.