Phaeoclavulina abietina

The most reliable way to identify Phaeoclavulina abietina is its bruising reaction: fresh tissue darkens to olive green or dark olive green wherever it is injured, standing out against its normal medium yellow-green to light olive color. The fruit bodies are small, standing 2 to 5 centimeters tall and 1 to 5 centimeters wide, branching from a central stem up to five times into slender, slightly flattened branches that fork or form crests near their tips.

The stem measures 5 to 15 millimeters long and 2 to 10 millimeters thick, with a mat of mycelium at its base connecting to rhizomorphs that branch into the substrate below. The tissue is leathery in texture and becomes brittle once dried. Its odor ranges from indistinct to earthy, and the taste starts sweet before turning somewhat bitter.

Spores collected in mass appear dark orange-yellow. Individually they are pip-shaped to broadly elliptical with one oblique end, measuring 6 to 9 by 3.5 to 4.5 micrometers, and are borne on four-spored basidia with sterigmata up to 7 micrometers long.

Phaeoclavulina abietina grows on the ground in the duff of coniferous forests, appearing scattered or in groups, sometimes arranged in rows. In North America it occurs in the United States, including the Pacific Northwest, and in Mexico, and it is also recorded in Europe.

Fruiting timing differs by region within the United States: on the West Coast it appears mostly from October to February, while inland populations tend to fruit from July to October. Observation records show a pronounced late-summer to autumn peak, consistent with its association with cooler, wetter conditions in conifer duff, though these records reflect presence rather than actual abundance.

1. Its scientific description traces back to Christian Hendrik Persoon, who originally named it Clavaria abietina, with a related name, Clavaria ochraceovirens, also given by Franz Wilhelm Junghuhn.
2. The species now carries the genus name Phaeoclavulina, reflecting a later reclassification credited to the mycologist Giachini.