Yellow stagshorn or Scarlet caterpillarclub

There's no cap. The fruit body is bushy: from a short base it forks into slender branches a few millimetres thick, with pointed, often forked tips, 3 to 6 cm tall and occasionally 10 cm. Small specimens can be simple spikes forked at the top.

The colour ranges from egg-yolk yellow to orange-yellow, with a paler, whitish-yellow base. It reddens as it dries. In wet weather the surface is greasy and sticky.

There is no cap. Its place is taken by the head, the fertile upper part of the club: 0.5–4 cm long and a few millimetres up to 1 cm thick. It's slightly swollen, cylindrical or a little flattened, and only rarely forked.

The colour is bright orange, scarlet orange or orange yellow. The surface is dry and finely pimply: each pimple is the opening of a tiny fruiting chamber. This rough head is what separates it from the smooth orange clubs of Clavulinopsis.

There are no gills or pores: the spores form over almost the whole surface of the branches except the base.

The spore print is whitish to pale yellow.

There are no gills, tubes or spines. The spores ripen in tiny flask-shaped chambers (perithecia) sunk into the surface of the head and escape through their openings, which is why the head looks pimply.

The spores are thread-like with many cross walls and break into small part-spores 2–4.5 × 1–1.5 µm. The spore print is white. You don't need a microscope in the field: the pimply head and the pupa at the base are enough.

There's no separate stem. The short, paler base roots deep into the wood.

The stem is 1–3 cm long and about 1–1.5 mm thick, often slightly wavy, paler than the head, pale orange and smooth. There is no ring and no volva.

At the bottom the stem narrows and runs down into soil or moss to a moth pupa, more rarely a caterpillar. The pupa is mummified, filled with the fungus and wrapped in white mycelium. To see it, gently loosen the soil around the base with your fingers rather than pulling the club out.

The flesh is springy, rubbery-gelatinous and cartilaginous, bending rather than snapping. It turns hard when dry.

The flesh is thin, whitish to pale orange and watery, with a thin firmer outer layer. There is no milk. Colour change on cutting isn't described in the sources.

The smell and taste aren't distinctive.

The smell is faint and indistinct, and field guides don't give one. It doesn't help with identification: look for the pimply head and the pupa in the soil instead.