Aniseed Funnel Identification Guide

The first impression

Aniseed Funnel is one of the few woodland mushrooms you may smell before you see. Walk a beech or oak wood on a still, damp October afternoon and a faint sweet aniseed note can drift across the path; follow it and you will usually find a troop of blue-green caps sitting in the leaf litter within a few metres. The colour is the second signal. There are very few green agarics in temperate woodland, and this one wears a soft, dusty verdigris or sea-green that looks almost like weathered copper.

The fruitbodies grow scattered, in loose troops, in arcs or in rings on the litter layer of deciduous and mixed woodland, never on standing wood. A typical group has caps at several ages, which is useful because young and old specimens of this species look surprisingly different.

Reading the cap

Young caps are convex with a strongly inrolled margin and a matt, faintly frosted surface, three to eight centimetres across. As they age they flatten, then depress in the centre, and finally become shallowly funnel-shaped, which is where the common name comes from. The outline is often irregular, wavy or lobed rather than a neat circle, especially where caps have grown up against twigs and leaves.

Colour is the character to record carefully because it fades. A fresh young cap is blue-green, greenish-grey or a distinct verdigris. With age, sun and drying it drains to greenish-buff, pale grey-green, ochre-cream or almost white, sometimes retaining green only near the margin or in the depressed centre. The surface is smooth and dry, without scales, and it is not viscid or slimy. In wet weather it can look slightly darker and more translucent at the very edge, but it never becomes glutinous.

A whitish form occurs that lacks the green pigment entirely. If you find one, the rest of the character set has to carry the identification.

Gills, stipe and base

Turn a cap over. The gills are the second pillar of the identification: they are decurrent, running visibly down onto the stipe, moderately crowded, fairly narrow, and whitish to pale cream, sometimes with a greenish or greyish-green wash when young. Gill edges are even. A useful genus-level check is to slide a thumbnail under the gills near the margin; in Clitocybe they separate from the cap flesh relatively easily as a sheet.

The stipe is three to six centimetres long and half a centimetre to a centimetre thick, cylindrical or slightly widened and club-shaped toward the base, often curved where it has pushed through litter. It is concolorous with the cap or paler, greenish-white to pale buff, and finely fibrillose or silky under a lens. There is no ring and no volva.

At the base, look for a felted pad of white mycelium binding leaves, twigs and needles into a small mat. Lifting a fruitbody usually brings a clump of glued litter with it. That litter-binding base is characteristic of a litter-decomposing woodland Clitocybe.

The flesh is white to very pale greenish-white, soft, thin in the cap and slightly fibrous in the stipe. Cut it lengthwise and watch for a minute: there is no colour change, no reddening, no blueing, no latex.

The aroma

The smell is the character everyone remembers and it is genuinely diagnostic when combined with the green cap. It is a strong, sweet aniseed or fennel-like aroma, obvious without crushing the fruitbody, and strong enough that a basket of specimens will scent a room. Crushing the flesh intensifies it. Unusually, the aroma survives drying, so a herbarium packet opened months later still carries it. If a green-capped funnel in front of you smells only mealy, mushroomy or unpleasant, it is not this species.

Taking a spore print

Cut the stipe flush with the gills, set the cap gill-side down on half-black, half-white card, cover it with a bowl to keep the air humid, and leave it four to eight hours. The deposit is white to very pale cream, occasionally described as carrying an extremely faint pinkish tone in a thick print, but never salmon, never brown, never purple-black.

That white print is the most important exclusion test for this species, because the one look-alike that shares the blue-green colour has a dark spore deposit. Take a thick print if you can and view it in good light against both the white and the black halves of the card.

Substrate and season

Aniseed Funnel is a litter decomposer. It fruits on the deep leaf layer of deciduous and mixed woodland, with beech and oak the most frequent settings, and it also occurs under birch, hazel and in conifer or mixed plantations on needle litter. It is not a wood decayer of logs and stumps, and it does not fruit in open grassland away from trees.

The season is autumn, from late August or September through November, sometimes lingering into early winter in mild years. Fruiting is gregarious, and the same patch of woodland floor tends to produce year after year because the mycelium persists in the litter layer, decomposing fallen leaves and returning nutrients to the soil.

Separating it from look-alikes on morphology alone

Clitocybe fragrans and its relatives in the fragrans group share the strong aniseed aroma, which surprises people who assume the smell alone is diagnostic. They are separated on colour and build: their caps are whitish, buff, pale tan or watery cream with no green whatsoever, they are thinner-fleshed, more hygrophanous and usually smaller, with a more slender stipe. If it smells of aniseed and is green, it is odora; if it smells of aniseed and is plain pale, work through the fragrans group.

Stropharia aeruginosa and Stropharia caerulea are the classic colour traps, being vividly blue-green. Everything else differs. Their caps are slimy and glutinous when moist, often decorated with white veil scales near the margin; their gills are adnate, not decurrent, and darken to grey-brown then purple-brown as the spores mature; they have a ring or a ring zone on the stipe; and the spore print is dark purple-brown. The gill attachment, the slime and the print separate them instantly.

Clitocybe nebularis shares the funnel form and decurrent gills but is much larger, grey to grey-brown with a frosted bloom, has no green tint, and has a strong sweetish-mealy odour rather than aniseed.

Infundibulicybe geotropa and Infundibulicybe gibba are tan to pinkish-buff funnels with decurrent gills and white prints, but neither is green and neither smells of aniseed; gibba is smaller with a pinkish-tan cap, geotropa is large, pale and often ringed in grassy rides.

Green-tinged Russula and green Cortinarius species can catch the eye at a distance but fail on structure: Russula has brittle, granular flesh that snaps like chalk and equal or adnexed gills, while Cortinarius shows a cobwebby veil and a rusty-brown spore print.

Field checklist

Blue-green to verdigris cap fading paler with age; convex then flattened then shallowly funnel-shaped with a wavy outline; decurrent whitish to pale greenish gills; pale greenish-white fibrillose stipe with a litter-bound white mycelial pad at the base; white to cream spore print; strong aniseed aroma that persists in dried material; autumn, on leaf litter under broadleaved or mixed trees.