[2] Clavulinopsis fusiformis forms cylindrical, bright yellow fruit bodies that grow in dense clusters on the ground in agriculturally unimproved grassland or in woodland litter.

[5] Initial molecular research, based on cladistic analysis of DNA sequences, indicates that C. fusiformis is part of a complex of related species.

[6] The fruit bodies of Clavulinopsis fusiformis are cylindrical, bright yellow, up to 150 x 10 mm, growing in fasciculate (densely crowded) clusters.

[7] In European grasslands, Clavulinopsis helvola, C. laeticolor, and C. luteoalba have similarly coloured, simple fruit bodies but are typically smaller and grow singly or sparsely clustered.

The uncommon Clavaria amoenoides produces densely clustered fruit bodies but they are pale yellow and, microscopically, lack clamp connections.