As a group they show a huge range in vegetative form, terrestrial or epiphytic, and can be found as tall cane-like plants a metre or so high, clumped or trailing, pendent or climbing, erect or creeping, tufted and tiny, delicate moss-like species that can grow on the thinnest of twigs.
Their flowers are among the most diverse and unusual, although often very small, and specialize in using tiny insects such as gnats or Chalcid wasps for pollination.