Diana: K. Kubitzki says: "Flowers declinate to pendent; perigone tubular variously colored but usually tipped green; tube short. Stamens free or proximally connate, inserted at the perigone throat; the free filaments winged below, but always with a slender tooth on each side above the middle. Stigma shortly 3-lobed. Seeds discoid, testa black. 2n = 46. Four spp., southern Peru to Bolivia." Arnold