Candelabrum desmidiaceum sp. nov. and C. clathrosphaeroides sp. nov. are illustrated and described. Morphologically, they represent a new type of conidium development previously unknown in Candelabrum: the formation of a basal plate by dicho- or trichotomous branching of the conidial body in combination with branches growing upwards at the outer margin of the basal plate which are distinctly verrucose outside, forming a hollow sphere enclosing an air bubble in the centre. In Austria, both species were found mainly on submerged beech leaves, but in the U.S.A., C. clathrosphaeroides was isolated from submerged leaves of many different deciduous species, indicating a wider host range. Both species are aero-aquatic fungi, and C. clathrosphaeroides, at least, is widely distributed in temperate climates. A key to the species of Candelabrum is provided.