C. fruticulosa often produces extensive fruitings covering tens or hundreds of cm2.

Often abundant on fallen beech logs, it also occurs on conifers and leaf litter.

C. fruticulosa, Slovakia, Sept 2017.

Colour forms in pale pink, blue or yellow are not uncommon. This bright yellow example was sent to me by Peter Thompson.

Ceratiomyxa fruticulosa (F. Muell.) T. Macbr.

Ceratiomyxa fruticulosa (F. Muell.) T. Macbr.

Unique among slime moulds.

7th February 2020

Ceratiomyxa is placed in its own order, the  Ceratiomyxomycetes, separated from the True Slime Moulds, the Myxomycetes as its spores are borne externally, rather than within enclosing fruit bodies (sporocarps).

Sporocarps are clustered on an inconspicuous spreading hypothallus, in the form of finger-like or branched processes up to 4mm tall, erect or nodding, on which the spores are borne singly at the tips of fine thread-like stalks.

C. fruticulosa, Nagshead June 2018

Unlike the true Slime Moulds, the spores of Ceratiomyxa are born externally on fine, almost invisible stalks. They are smooth, colourless and oval, 10-14 x 6-8 µm Ø. Under suitable lighting conditions they can be seen clearly against a dark background with a hand loup.

C. Fruticulosa var. arbuscula differs from the type in its bushy habit, but intermediates seem to occur, and this may be one.

Sometimes considred merely as a subspecies of C. fruticulosa, Ceratiomyxa porioides, rare in Britain is not uncommon in Central and Southern Europe, and may be expected to become more common in Britain with climate warming. It resembles a poroid fungus such as Trechispora mollusca, but is more delicate to the touch. Holm Fen, October 2001.