Scorias spongiosa

The aphids accumulate in late summer and autumn, forming large colonies. Spores of Scorias spongiosa are borne by wind and rain and fall on the honeydew secretions found below the aphids. The first hyphal growth is straw coloured and unpigmented. The hyphae adhere to each other for short distances, diverging and re-adhering to form a loose stranded structure. Pigmentation begins to occur on the surfaces of outer strands and the stroma begins to darken. The hyphae coalesce and form mycelial strands which radiate outward and upward from the supporting structure.^[3] Flask-shaped, spore-bearing pycnidia appear on the mycelia, which have a waxlike appearance: the matrix turns from brittle to soft as it absorbs moisture.^[4] As further quantities of honeydew accumulate, the fungus grows larger until it resembles a gelatinous sponge resting on the branches or leaves of the beech tree. Fully pigmented strands in the mature stoma produce bowl-shaped pseudothecia and these outermost hyphae cease to grow. The inner strands continue growth and force their way to the exterior. Asexual conidia are extruded in a slimy matrix in liquid droplets from the pycnidia. As time passes the stroma becomes a spongy black mass and produces sexual spores called ascospores in the pseudothecia, which remain embedded in the stroma.^[2][3]

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  Beech branch covered in beech blight aphids and S. spongiosa
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  Young, unpigmented S. spongiosa specimen growing on a beech branch
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  Patches of S. spongiosa growing on a beech trunk
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  S. spongiosa growing on the base of a beech tree covered in honey dew
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  Mature S. spongiosa stroma

Apiosporina morbosa appears on cherry and plum trees and their relatives.^[5]