This is on a leaf and I thought these grew on wood. Possibly wrong ID.
Growing on a mossy log
1st picture is day 1, streaming stage. 2nd picture is day 2, fruiting bodies
Stemonitis is a distinctive genus of slime moulds found throughout the world (except Antarctica). They are characterised by the tall brown sporangia, supported on slender stalks, which grow in clusters on rotting wood. Identification within the genus is difficult, and can only be performed with confidence using a microscope.