Clavulinopsis helvola

Clavulinopsis helvola is a clavarioid fungus in the family Clavariaceae, known in the United Kingdom by the recommended English name yellow club. Its fruiting bodies are slender, cylindrical to narrowly club-shaped and lemon yellow to deep yellow, reaching up to about 60 millimetres tall and 3 millimetres wide, with an indistinct stem. Under the microscope the spores are colourless, roughly round to ellipsoid and carry large but sparse spines. The species was first described from Europe in 1797 by Christiaan Hendrik Persoon, and E. J. H. Corner moved it into the genus Clavulinopsis in 1950, although Ron Petersen placed it in Ramariopsis in 1978. It grows singly or in small clusters on the ground, in unimproved grassland or woodland litter, and is widely distributed across Europe with reports from Asia and the Americas. It can be confused with Clavulinopsis laeticolor, C. luteoalba and C. fusiformis.