Highlighted articles for February 2022

Abstract

The flora of Hawaiʻi diversified as species colonized different islands. Patterns of morphological radiation within plant lineages provide evidence of this evolutionary process, but Powers et al. show that volatile chemicals in floral scent vary within a single species. Wind-pollinated Schiedea globosa likely descended from moth-pollinated ancestors and produces scent that intensifies at night, but shares few compounds with the nocturnal scents of two moth-pollinated relatives. Males emit more scent at night than females, and their blend is quantitatively richer in ketones and nitrogen-containing aldoximes. Comparing populations across the archipelago grown in a common environment shows that divergence in scent is correlated with genetic divergence in males, but has a more complex relationship with geographic distance. Chemical diversity in this species along the axes of space, sex, and time suggests that this variation can persist in the absence of selection by pollinators.