Nectria cinnabarina (Tode) Fr. - Coral Spot

Distribution - Taxonomic History - Etymology - Identification - Reference Sources

Nectria cinnabarina - Coral Spot

Taxonomy

Phylum: Ascomycota

Class: Sordariomycetes

Order: Hypocreales

Family: Nectriaceae

Coral Spot, a weak pathogen of broadleaf trees, goes through a spongy conidial stage (producing asexual spores) and a tough perithecial stage (producing sexal spores) that at a glance look quite similar. Beech is the main host, but this colourful parasite is also fairly common on Sycamore, Horse Chestnut and Hornbeam, but hardly ever on conifers. Particularly susceptible are trees that have already been weakened by other stressing factors such as drought, another fungal infestation or physical damage.

Nectria cinnabarina - Coral Spot , conidial stage

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.

Distribution

Nectria cinnabarina is common and widespread throughout Britain and Ireland as well as other parts of mainland Europe, wherever broadleaf trees grow.

Left: the conidial stage of Coral Spot fungus Nectria cinnabarina. This picture, which was taken in Norway during April 2014, has been kindly contributed by Arnor Gullanger.

Taxonomic history

The basionym of this species was defined when, in 1791, German mycologist and theologian Heinrich Julius Tode (1733 - 1797) described this ascomycetous fungus under the scientific name Sphaeria cinnabarina. It was Swedish mycologist Elias Magnus Fries who transferred this species to the Nectria genus in 1849, whereupon its currently-accepted scientific name Nectria cinnabarina was established.

Nectria cinnabarina (Tode) Fr. has several synonyms including Tremella purpurea L., Sphaeria cinnabarina Tode, Tubercularia confluens Pers., Sphaeria fragiformis Fr., and Nectria ochracea Grev. & Fr.

Etymology

Nectria, the genus name, comes from the same stem as necrosis and means 'killer'. The specific epithet cinnabarina is equally obvious: it means cinnabar coloured (like red lead).

Identification guide

Close-up of Nectria cinnabarina

Description

Pink blobs, turning eventually to a reddish brown and becoming very hard. The individual blobs are 1 to 4mm across.

 

Ascospores

Cylindrical, smooth, 12–25 x 4–9µm, 1-septate; hyaline.

Spore print

White.

Odour/taste

Not distinctive.

Habitat

Weakly parasitic and then saprobic, on twigs of Beech and occasionally other deciduous hardwoods; rarely on conifers.

Season

Mainly summer and autumn in Britain and Ireland, but some fruitbodies can often be found throughout the year.

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.

Reference Sources

Fascinated by Fungi, Pat O'Reilly 2011.

Dennis, R.W.G. (1981). British Ascomycetes; Lubrecht & Cramer; ISBN: 3768205525.

Breitenbach, J. & Kränzlin, F. (1984). Fungi of Switzerland. Volume 1: Ascomycetes. Verlag Mykologia: Luzern, Switzerland.

Medardi, G. (2006). Ascomiceti d'Italia. Centro Studi Micologici: Trento.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.

Other web pages about this species

Roger Phillips (UK)