slime mold, Mucilago crustacea

Description:

Mucilago crustacea is a slime mould. The plasmodium ( an amoeboid mass) is yellow, white or cream coloured and it creeps on the substrate as it grows, being able to even climb twigs or herbs adopting a vertical position. During that movement it leaves the hypothallus, a kind of membranous and calcareous trail that is usually found close to the fruiting bodies. When the conditions are good it produces the aethalia, fruiting bodies, 4-10 cm long, sessile, from pale yellow colour to white when mature. The shape is variable depending on the place where it forms. The peridium or external shell is formed by calcium crystals (?) that give the white colour, but when washed by the rain it shows the dark coloured spores mass in the interior. It has a columela that gives support to sterile anastomosed fillaments, called capillitia, that end in a pointed shape and have wide nodule with darker colour in contact zones. Inside the aetalia form the spores, dark in colour, 10-14 microns, with a globe shape and decorated with 1 micron long spines.

Habitat:

Open pine tree and Holm oak forest