Cyttaria gunnii (Beech strawberry)
Species: C. gunnii
Binomial name: Cyttaria gunnii
Synomyn: Cyttaria purdiei
Common names: Beech strawberry, Myrtle orange
Cyttaria gunnii commonly is an orange-white coloured ascomycete fungus present in New Zealand and Australia. This fungus is present throughout New Zealand, wherever the host tree Fuscospora fusca (Red Beech) is found. In Australia its host tree is Fuscospora cunninghamii (Mytle beech).
Germinatinating spores invade the tissues of new shoots and produce chemical substances which causes the proliferation of the host tissue and lead to the production of localised galls. The globose, woody, galls are perennial and produce clusters of fruiting bodies late spring and summer (November to January). As the fruiting bodies grow they cover and obscure the small gall on which they are borne.
The immature fruiting bodies are lighter in colour than the mature honey combed fruiting bodies which are a fawn to bright yellow colour. They are up to 2.5 cm in diameter and are covered by a membrane that bursts, uncovering a network of concavities. The spore print is black and the spores measure 12 by 7–12 μm and are discharged in visible clouds.
Diagnostic features of Cyttaria gunnii are:
1 The galls on branches are rarely more than twice the diameter of the host branch, and usually occupying about two-thirds of its circumference.
2 The galls on the stems usually form encircling bands.
3 The bark under the gall is contorted and has sharp spines.
Beech strawberry galls with a section of the outside membrane removed showing the internal honey comb construction.