Description Robert John Thornton was an English physician and botanical writer, noted for 'A New Illustration of the System of Carolus Von Linnaeus' (1797-1807) and 'The British Flora' of 1812. 'The Night-Blooming Cereus,' or Queen of the night (Selenicereus grandiflorus) is an engraving by Robert Dunkarton after a painting by Philip Reinagle and Abraham Pether for 'The Temple of Flora,' by British botanist Robert John Thornton, 1800.