The fruit bodies are small (c. 0.5mm diameter) black, rounded-conical fruitbodies embedded in nettle stems.  Prominent chimney-like or nipple-like ostioles break through the outer surface of the nettle stem, often in large numbers.  Spores are released through the ostioles, and are pale yellow-brown with between 4 and 13 septa or divisions.  This is variable, and different information sources give different number of septa.

[Thompson (2013) has 6 - 12 septa; Breitenbach & Kranzlin (1984) have (4) 6 - 11 (13) septa; Laessoe and Petersen (2019) have 5-9 celled.] 

Leptosphaeria doliolum is also found on nettle stems, and has a simlar shape but with 2 concentric raised rings on the fruitbody.  It has 3-septate/4-celled spores.  It has occasionally been recorded in VC55.  There are many other species associated with different hosts.

Photograph on host; note substrate and associated plant species.  Clear photos of individual fruitbodies are needed in order to separate this from other species on nettle; microscopic examination or confirmation by an expert may be needed 

Found growing clustered at the bases of dead stems of Common Nettle.

Maturing in late winter and spring, though fruit bodies may be seen throughout the year.