Anamorph: no information available.
Teleomorph: stromata cylindric-clavate, whitish to pale yellow, finely tomentose. Stalk to ca 13 x 0.5-0.7 mm, cylindrical, slightly flexuose, sometimes branched. Fertile head 3-6 x 1-1.8 mm, cylindric-fusiform. Ascomata perithecia, 150-170 µm diam. and ca 300 µm tall, obpyriform with a tapering conical neck, immersed with strongly protruding apices, yellowish. Interascal tissue not seen. Asci 200-220 x 3-4.5 µm, narrowly cylindrical, slightly narrower in the central portion, with a conspicuous hemispherical apical thickening penetrated by a narrow pore, 8-spored. Ascospores arranged in a fascicle, 145-220 µm long, narrowly bifusiform, the central part filiform, ca 0.5 µm diam., without distinct septa and almost devoid of cytoplasm content, the terminal parts narrowly fusiform, ca 30 x 1.5 µm, 3-septate, the septa narrow and inconspicuous, hyaline, thin-walled, smooth, without an epispore, gelatinous sheath or appendages.
Not formally assessed in GBI. Only one collection is known, but earlier records could have been misidentified. Even if that is the case, the species is likely to be listed as at least Vulnerable.
Cordyceps tuberculata appears similar externally to this species, but has narrowly cylindrical ascospores without a central narrow part, and which fragment into part-spores.
Parasitic on larvae of Lepidoptera. The host organism is not known for the British collection.
In GB&I, only recorded from VC41 Glamorgan.