Plagiolirion is a genus of Colombian plants in the Amaryllis family.

[2][3] It contains only one known species, Plagiolirion horsmannii,[2][3] rare in the wild and for several years thought extinct until rediscovered in the Río Cauca Valley in 1989.

[4] It has showy, white flowers.

[5][6] The diploid chromosome number of Plagiolirion horsmannii is 2n = 46.

[4]