Acianthera is a genus of orchids native to the tropical parts of the Western Hemisphere,[1] especially Brazil.

[2] It was first described in 1842[3] but was not widely recognized until recently.

Most of the species were formerly placed under Pleurothallis subgenus Acianthera.

This splitting is a result of recent DNA sequencing.

As of October 2022[update], Plants of the World Online accepted about 300 species within Acianthera:[4]