Achlya is a genus of oomycete (water mold), in the family Saprolegniaceae. The genus includes several plant pathogens including Achlya conspicua and Achlya klebsiana. Unlike many other microorganisms, cell expansion is governed by changes in cell wall strength rather than changes in osmotic pressure. The genome of Achlya hypogyna has been sequenced and can be accessed on public online databases, for example on the NCBI website (National Center for Biotechnology Information). The genus was first circumscribed in Nova Acta Phys.-Med. Acad. Caes. Leop.-Carol. Nat. Cur. vol.11 on page 514 in 1823 by Christian Gottfried Daniel Nees von Esenbeck. The type species is Achlya prolifera. The genus name of Achlya is named after Achlys, who in the Hesiodic Shield of Heracles, is one of the figures depicted on Heracles' shield, perhaps representing the personification of sorrow. Several Achyla spp. are pathogens of rice seedlings.

Species

As accepted by Species Fungorum; Former species; (all are Saprolegniaceae family)