Geosiris aphylla is a species in the Iridaceae family of flowering plants, first described in 1894. It is endemic to Madagascar. Geosiris aphylla is sometimes called the "earth-iris". It is a small myco-heterotroph lacking chlorophyll and obtaining its nutrients from fungi in the soil. Its rhizomes are slender and scaly, and stems are simple or branched. The leaves are alternate, but having no use, are reduced and scale-like (hence the epithet "aphylla," meaning "without leaves"). The flowers are light purple.