Wrinkled Club Identification Guide

What You See First

The find usually happens at ankle height, on a mossy bank or a shaded path edge in the second half of the year. A scatter of small white to cream fingers stands upright among conifer needles or leaf litter, each one three to ten centimetres tall and rarely thicker than a pencil. From standing height they read as a pale smudge on the ground; crouch down and the smudge resolves into slender clubs, some simple and blunt, others split near the top into two or three short antler-like prongs. Nothing about them is glossy or gelatinous. The overall impression is of a dry, chalky, slightly crumpled candle that someone has squeezed while it was still soft.

Reading the Shape

Clavulina rugosa is a club fungus, so there is no cap, no gill surface and no true stipe to work through in the usual order. The whole upright body is the fruit body, and the fertile layer is smeared over its outer surface from a little above ground level right to the tips. Begin at the base: it is narrow, often faintly downy where it meets the soil, and frequently bound into the litter by fine white mycelial threads that lift a plug of needles when you pull. Follow the club upward and note that it thickens gradually rather than abruptly, is often laterally compressed rather than truly cylindrical, and may twist along its length. The tips carry the most information. They are blunt, sometimes looking bitten off flat, and where branching occurs it is sparse, irregular and usually confined to the upper third.

The Wrinkles

The name does the work here. Run a thumbnail down the side of a fresh club and you both see and feel longitudinal grooves, low ridges and irregular folds. Some individuals are strongly fluted along their whole length; others show only a few shallow channels near the apex, so check several fruit bodies from the same troop before deciding. Under a hand lens the surface is matte and minutely uneven, never smooth and porcelain-like. This sculpturing, combined with sparse blunt branching, is the quickest way to place a white club in this species while you are still standing over it.

Colour, Flesh and Colour Change

Fresh material is white to ivory, ageing to cream, with the base often dulling to buff or pale ochre. Split a club lengthwise: the flesh is white, solid to slightly fibrous, and it does not change on exposure. There is no latex, no reddening, no blueing. One colour phenomenon is worth learning because it catches people out every autumn. Clavulina fruit bodies are routinely attacked by a small parasitic ascomycete that converts them to a smoky grey from the base upward and gives the surface a faintly velvety, blotched appearance. A grey club with the same fluted outline and the same blunt sparse tips is still this species wearing a parasite, not a different fungus.

Taking and Reading a Spore Print

Club fungi print perfectly well, they just need a slightly different setup from a capped mushroom. Cut two or three mature clubs at ground level, lay them on their sides across a sheet of dark paper or a strip of glass over dark card, and cover them with an upturned bowl to hold humidity. Leave them several hours or overnight in a cool room. What you want is a fine dust along the length of the club, and in this species it is white to very pale cream. That white print rules out a large slice of the coral-shaped fungi immediately, because the big fleshy Ramaria corals drop ochre to yellow-brown spores. Under a microscope the spores are broadly ellipsoid to almost round, smooth and colourless, and the basidia carry only two sterigmata rather than the usual four, which is the defining feature of the whole genus.

Substrate, Season and Setting

This is a soil fungus, not a wood fungus, and that single observation settles many identifications. It fruits from the ground among litter, moss and needle duff, most often in conifer or mixed woodland, along path banks, in old plantations and on humus-rich soil under birch and pine. It forms mycorrhizal partnerships with trees, so it recurs in the same spots year after year and never appears on stumps, logs or woodchip. The season runs from late summer through autumn and often into early winter, since the clubs tolerate a light frost better than most soft-fleshed fungi. Fruiting is typically in scattered troops or small clusters with two or three clubs fused at the base.

Separating the Closest Look-alikes

The crested coral, Clavulina coralloides, shares the same white colour, the same soil habitat and the same two-spored basidia, but it branches repeatedly from low down and its branch tips are finely divided into pointed crests, like a tiny cauliflower or a frayed rope end. Wrinkled Club branches sparingly if at all, and its tips stay blunt. Grey coral, Clavulina cinerea, is more richly branched and ash-grey throughout from the start, which is a different look from a parasitised specimen where the grey creeps upward over a fluted club.

White spindles, Clavaria fragilis, is the other frequent confusion. It grows in dense tufted bundles of many slender, unbranched, smooth-sided clubs with tapered, often pointed tips, it is extremely brittle and usually hollow, and it favours unimproved grassland, lawns and mossy churchyards rather than woodland litter. The absence of surface flutes plus the fascicled growth habit is enough. Clavaria acuta is smaller, solitary, sharply pointed and typically sits on bare soil banks.

Ramariopsis kunzei is white but branches profusely and finely from a short stem, with slender pointed tips, and its spores are minutely ornamented rather than smooth. Finally, the thread-like Typhula and Macrotyphula species are far more slender, wiry and often stalked, with a distinct smooth fertile head, and they usually arise from a buried leaf or twig rather than from soil.

Field Checklist

• Simple or sparsely forked white clubs, 3 to 10 cm tall, growing from soil and litter
• Surface longitudinally grooved, folded and matte, never smooth and glossy
• Tips blunt or flattened, branching restricted to the top third if present
• Flesh white, unchanging when cut, no latex
• Spore print white; basidia two-spored
• Woodland soil, conifer or mixed, late summer into early winter
• Grey specimens are usually parasitised individuals, not another species