“…About one third of the ~275,000 angiosperm species produce flowers with petals fused into a corolla tube (i.e., sympetalous), forming a protective enclosure of nectaries and reproductive organs. Corolla tubes have evolved multiple times independently across the angiosperm tree of life (Endress, 2011), most notably in the common ancestor of the Asterids, a clade containing more than 80,000 species (Schonenberger and Von Balthazar, 2013). Subsequent elaboration in length, width, and curvature has led to a great variety of corolla tube shapes that enabled asterid species to exploit many specialized pollinator groups (e.g., beeflies, hawkmoths, hummingbirds, nectar bats), which in turn drives rapid plant speciation (Muchhala, 2006;Hermann and Kuhlemeier, 2011;Paudel et al, 2015;Lagomarsino et al, 2016).…”