Nectria cinnabarina
Description
Nectria cinnabarina is a weak pathogen of broadleaf trees, goes through a spongy conidial stage (producing asexual spores) and a tough perithecial stage that at a glance look quite similar. Beech is the main host, but this colorful 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.
When you find this species this mushrooming season, you will note that there are slightly larger, different colored, soft tissue globules growing on the same twig or branch. Before Nectria cinnabarina was fully understood, these separate structures were described as another species; Tubercularia vulgaris. As it turns out that these paler, light pink or faint orange structures are the asexual forms of this species, while the hardy perithecial fruiting bodies represent its sexual form. The asexual pustules consist of a dense tuft of conidiophores termed the conidial stroma .
Common names: Coral Spot.
Mushroom Identification
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.
Habitat & Ecological Role
Weakly parasitic and then saprobic, 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.
Similar Species
There are several other reddish Nectria species and they are difficult to separate using macroscopic characters alone.
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.
Nectria, the genus name, comes from the same stem as necrosis and means 'killer'. The specific epithet cinnabarina is equally obvious: it means cinnabar colored (like red lead).
Life Cycle
Nectria galligena overwinters in the callus tissue growing slowly while its host is dormant. During moist periods, creamy white cushion-like fruiting structures will develop. These are followed by a second type of reproductive structure, which is red to reddish-orange, pin-head sized, and lemon-shaped, in autumn through spring. During rain or other moist weather, spores are released and dispersed by wind or water infecting susceptible plants through natural openings such as leaf scars or wounds from improper pruning, sunscald, storm damage, frost cracks, or other mechanical damage. As the fungus grows, it kills bark, cambium, and the outermost sapwood.
The life cycle of the Nectria dieback fungus is similar to that of Nectria canker. Creamy to coral pink to pink-orange or light purplish red spore-producing structures develop in spring or early summer. These will age to tan, brown, or nearly black. Orange-red fruiting structures, which mature to dark reddish-brown and may persist through winter, are produced in summer and autumn. Both structures release spores that are dispersed by water and can invade susceptible tissue producing cankers and dieback.
Treatment
Proper selection
Choose trees and shrubs that are well adapted to the climate of the area to minimize infection due to freeze damage and other environmental stresses.
Maintain plant vigor
Keep plants healthy and growing vigorously by using good cultural techniques. These include choosing the appropriate planting site, watering during dry periods, using mulch around the base of the tree or shrub and fertilizing and pruning properly. Pruning is best done in late winter. Avoid pruning in spring when higher moisture can increase the risk of infection or in late summer and autumn, which can delay the plant’s natural cold hardiness response. Minimize any wounding due to root pruning, transplanting or lawnmowers to reduce infection sites.
Prune
Prune out branch cankers during dry periods when conditions are unfavorable for infection. Disinfect pruning tools in a 1-part bleach to 9-parts water solution between each cut.
Photo sources:
Photo 1 - Author: Michel Langeveld (CC BY-SA 4.0)
Photo 2 - Author: Michel Langeveld (CC BY-SA 4.0)
Photo 3 - Author: Edward Bell (CC BY-SA 4.0)
Photo 4 - Author: Alexis Williams (CC BY-SA 4.0)
Photo 5 - Author: Michel Langeveld (CC BY-SA 4.0)
Color:Orange
Shape: Corticioid