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
ABC model of flower development "Arabidopsis", where they are also involved in controlling the development of carpels and the ovule and even with structures related to seed dispersal. The appearance of interesting phenotypes in RNA interference studies in "Petunia" and tomato led, in 1994, to the definition of a new type of function in the floral development model. The E function was initially thought to be only involved in the development of the three innermost verticils, however, subsequent work found that its expression was required in all the floral verticils. ABC model of flower development The ABC model of flower development is a scientific model