Blastocladia is a genus of aquatic fungi.
Blastocladia species have a thallus that consists of a single, branched basal cell or trunk with rhizoids at one end and sporangia at the other. They are not able to use oxygen, although its presence does not inhibit growth.
Members of Blastocladia grow on submerged twigs and fruit.
Blastocladia was circumscribed by German scientist Paul Friedrich Reinsch in 1877, who included a single species, Blastocladia pringsheimii. Roland Thaxter added a second species, B. ramosa in 1896. He placed the genus provisionally in the Pythiaceae owing to its resemblance of its resting spores to the conidia of some members of the genus Pythium. Joseph Schröter (1897) included it with the water mold family Leptomitaceae.
As of December 2015, Index Fungorum accepts 30 species in Blastocladia:
Blastocladia angusta A.Lund 1934Blastocladia arborata S.N.Dasgupta & R.John 1989Blastocladia aspergilloides Crooks 1937Blastocladia bonaerensis Steciow & Marano 2006 – ArgentinaBlastocladia caduca S.N.Dasgupta & R.John 1989Blastocladia coronata S.N.Dasgupta & R.John 1989Blastocladia didyma S.N.Dasgupta & R.John 1989Blastocladia elegans S.N.Dasgupta & R.John 1989Blastocladia excelsa S.N.Dasgupta & R.John 1989Blastocladia filamentosa S.N.Dasgupta & R.John 1989Blastocladia fruticosa S.N.Dasgupta & R.John 1989Blastocladia fusiformis S.N.Dasgupta & R.John 1989Blastocladia globosa Kanouse 1927Blastocladia glomerata Sparrow 1936Blastocladia gracilis Kanouse 1927Blastocladia heterosporangia S.N.Dasgupta & R.John 1989Blastocladia incrassata Indoh 1940Blastocladia mammillata S.N.Dasgupta & R.John 1989Blastocladia pileota S.N.Dasgupta & R.John 1989Blastocladia pringsheimii Reinsch 1877Blastocladia prolifera Minden 1912Blastocladia pusilla S.N.Dasgupta & R.John 1989Blastocladia ramosa Thaxt. 1896Blastocladia rostrata Minden 1912Blastocladia sessilis S.N.Dasgupta & R.John 1989Blastocladia sparrowii Indoh 1940Blastocladia spiciformis S.N.Dasgupta & R.John 1989Blastocladia strangulata Barrett 1912Blastocladia tenuis Kanouse 1927Blastocladia truncata Sparrow 1932