Summary:
Features of Nectria cinnabarina group include fruiting with many dense clusters (each with a more or less circular outline) of tiny cushion-shaped red to red-brown fruitbodies with an apical papilla, growth on hardwood, and microscopic characters. The pink to light red to light orange cushions of the conidial state (known as ''coral spot'') are usually associated. These anamorphs are Tubercularia vulgaris or close spp. |Hirooka(1) examined and sequenced collections labeled as this species and found at least four species: 1) Nectria dematiosa (up to 2-septate ascospores, stemless anamorphs, known from British Columbia, Poland, Japan, and New Zealand), 2) Nectria cinnabarina (up to 2-septate ascospores, anamorph fruitbodies predominantly (70%) long-stemmed, known from eastern North America and Europe), 3) Nectria nigrescens (up to 3-septate ascospores - 4% are 3-septate. 5% 2-septate, anamorph fruitbodies that are 65% short-stemmed and 35% long-stemmed, known from eastern North America and Europe), and 4) Nectria asiatica (up to 1-septate ascospores, anamorph fruitbodies short-stemmed, known from China and Japan). The length of the stems is not specified but the illustration of N. cinnabarina appears to show a stem almost as high at the rest of the fruitbody and almost as wide across as the fruitbody is across. Note that the stems of the stemmed anamorph antibodies may be obscured by masses of conidia so that they appear to be stemless. Note also that there are subclades within N. dematiosa that could represent separate species, but evidence is insufficient.

Microscopic:
spores 16-19 x 5.5-6 microns, cylindric-elliptic, smooth, colorless, slightly constricted with a septum in center; asci 8-spored, 75-90 x 9.5 microns, irregularly biseriate; paraphyses not observed, (Breitenbach), spores 12-25 x 4-9 microns, elliptic-cylindric, with median transverse septum, colorless; paraphyses branched, colorless, (Dennis), spores 12-20 x 4.5-6.5 microns, (Hansen, L.)

Notes:
There are collections labeled as Nectria cinnabarina at the University of British Columbia from BC, WA, and OR.