References in classic literature ?
Then there are to be eschscholtzias, dahlias, sunflowers, zinnias, scabiosa, portulaca, yellow violas, yellow stocks, yellow sweet-peas, yellow lupins--everything that is yellow or that has a yellow variety.
Handsome warm-weather bloomers, scabiosas (pincushion flowers) and stokesia (Stokes aster) can swathe gardens in tones from palest lavender to sky blue.