Orchidaceae tubers after detecting the plants underground by scent. Orchids have been used in traditional medicine in an effort to treat many diseases and ailments. They have been used as a source of herbal remedies in China since 2800 BC. "Gastrodia elata" is one of the three orchids listed in the earliest known Chinese Materia Medica ("Shennon bencaojing") (c. 100 AD). Theophrastus mentions orchids in his "Enquiry into Plants" (372–286 BC). Orchids have many associations with symbolic values. For example, the orchid is the City Flower of Shaoxing, China. "Cattleya mossiae" is the national Venezuelan flower, while "Cattleya trianae" is the
Basics of blue flower colouration Basics of blue flower colouration Blue flower colour was always associated with something unusual and desired. Blue roses especially were assumed to be a dream that cannot be realised. Blue colour in flower petals is caused by anthocyanins, which are members of flavonoid class metabolites. We can diversify three main classes of anthocyanin pigments: cyaniding type (two hydroxyl groups in the B-ring) responsible for red coloration, pelargonidin type (one hydroxyl group in the B-ring) responsible for orange colour and delphinidin type (three hydroxyl groups in the B-ring) responsible for violet/blue flower and fruits coloration. The main difference in the structure