Nectria cinnabarina - Coral Spot

Taxonomy

Class: Sordariomycetes

Order: Hypocreales

Family: Nectriaceae

Coral Spot is a weak pathogen of broadleaf trees. This gregarious ascomycete is hardly ever seen on conifers. Beech is the host most often infected, but this parasite is also fairly common on Sycamore, Horse Chestnut and Hornbeam. Particularly susceptible are trees that have already been weakened by other stressing factors such as drought, another fungal infestation or physical damage.

The effect of Coral Spot infection is that (usually small) twigs and branches die back, and then dense clusters of soft, pinhead-sized pink fungal blobs (the sexual stage in the complex lifecycle of this fungus) break through the thin bark. Later the blobs harden and turn dark reddish-brown (this is the conidial stage in the lifecycle), and by this time the infected timber is so weak that it tends to snap off during windy weather.

Identification Guide

	Description Pink blobs, turning eventually to a reddish brown and becoming very hard.
Dimensions	Individual blobs are 1 to 4mm diameter.
Spore print	Black.
Odour/taste	Not distinctive.
Habitat	On twigs of Beech and occasionally other deciduous hardwoods; rarely on conifers.
Season	Mainly summer and autumn, but some fruitbodies can often be found throughout the year.
Occurrence	Frequent.
Similar species	There are several other reddish Nectria species and they are difficult to separate using macroscopic characters alone; however, in Britain and Ireland Nectria cinnabarina is the most common of the group.