Cattleya Orchid and Three Hummingbirds 1870s. The NGA describes the work: "Lichen covers dead branches; moss drips from trees; and, a blue-gray mist veils the distant jungle. An opulent pink orchid with light-green stems and pods dominates the left foreground." On the right, two green-and-pink Brazilian Amethysts hover about a nest while a red-tailed Sappho Comet perches nearby. Cattleya Orchid and Three Hummingbirds Cattleya Orchid and Three Hummingbirds (1871) is an oil on mahogany panel picture by Martin Johnson Heade acquired by the National Gallery of Art in 1982. Inspired perhaps by the works of Charles Darwin and Frederic Edwin Church, Heade planned to produce
Basics of blue flower colouration of co-pigmentation, intermolecular and intramolecular. In the first type co-pigment is bound to anthocyanin by non-covalent bond (hydrogen bond, hydrophobic interaction, ionic interaction). In the second type, we can observe covalent acylation of the glycosyl moiety of anthocyanin. Intramolecular co-pigmentation has stronger effect on the colour. This type of protective stacking is called also a sandwich type stacking and is a very common mechanism in the formation of blue flower colour. Tirantin present in "Clitoria ternatea" (butterfly pea) and phacelianin present in "Phacelia campanularia" are examples of pigments with intramolecular co-pigmentation. Metal complexation: Often blue flower colour is correlated with