Living in the shadows: Gastrodia orchids lack functional leaves and open flowers

Abstract

Non-photosynthetic plants dependent on fungi have long fascinated botanists and mycologists. The genus Gastrodia (Orchidaceae) contains more than 100 achlorophyllous species, including some species recently discovered in Japan and Taiwan which produce only closed self-pollinating flowers. To date, Gastrodia is probably the only genus containing species with only closed flowers, which has been verified by a decade of monitoring hundreds of individuals. Here, the unique characteristics of the genus Gastrodia have been reviewed, emphasizing the reproductive biology of these newly described species that neither photosynthesize nor bloom. Investigation of such species that scarcely resemble other plants may paradoxically enhance our understanding of plants more broadly.