Fenugreek Milkcap Identification Guide

Wet ground and the first impression

Lactarius helvus is a fungus of wet, acid, peaty ground, and the habitat does much of the identification before you have touched the specimen. Picture yourself on the edge of a raised bog or a boggy hollow in a conifer plantation, with sphagnum underfoot, cotton-grass and purple moor-grass around, scattered birch and spruce or pine behind, and boots slowly sinking. Fruit bodies push up through sphagnum cushions or through a wet needle mat, singly or in scattered groups, sometimes in surprising numbers along a wet ride.

The first impression is of a large, pale, dry-looking mushroom in dull cinnamon or fawn tones, funnel shaped when mature and slightly shabby. It looks matt and slightly furry rather than glossy, and it is noticeably big for the genus, which is why it stands out among the smaller bog milkcaps.

Reading the cap

The cap is 5 to 15 cm across and occasionally reaches 20, which alone excludes most of the small birch and sphagnum milkcaps. It begins convex with a strongly inrolled margin, then flattens and finally becomes shallowly funnel shaped, sometimes retaining a low central bump.

The surface texture is the character to trust. It is dry and matt, finely felted or minutely scurfy, and often breaks into low granular scales towards the margin. Even in wet weather it is at most slightly tacky, never sticky or slimy. The colour is pale cinnamon-buff, greyish fawn, pinkish tan or pale leather, fading paler as it dries and sometimes showing faint concentric zoning or vague watery patches, but never strongly zoned.

Gills and the latex trap

The gills are adnate to slightly decurrent, fairly crowded but not tightly so, narrow, and pale cream to pinkish buff, deepening to yellow-buff or pale ochre with age. Damaged areas dry to rusty brown spots. Gills fork sparingly near the stipe.

Now the trap. Most milkcaps announce themselves with a bead of white latex the moment they are cut. This species produces latex that is watery and colourless, extremely sparse, and frequently invisible altogether, especially in dry weather or in old specimens. Do not conclude from a dry cut that you are not holding a milkcap. Instead, check the flesh: cut across the stipe and note whether it snaps with a chalky, granular break rather than tearing in fibres. Then look at a fresh gill cut with a lens under good light for a thin watery film. When latex does appear it does not change colour and leaves no stain on white tissue.

Stipe, base and flesh

The stipe is 5 to 10 cm long and 1 to 2.5 cm thick, cylindrical or slightly swollen in the middle, and stuffed at first, becoming hollow with a wide cavity. Its colour matches the cap or is a little paler, and the surface is dry and finely pruinose or downy rather than smooth and polished. There are no pits, no ring and no cortina. The base is usually clothed in pale mycelium with sphagnum strands and peat fragments woven in, so lift it carefully to see the attachment.

Section the fruit body. The flesh is pale buff, firm and brittle, thick in the cap centre and thin at the margin, and it does not change colour on exposure beyond a slight browning around the stipe cavity in age.

Odour, the deciding character

The scent is what settles this species, and it is worth taking trouble over. Fresh in the open air the smell can be surprisingly faint. Break a piece of cap, place it in a closed pot or a paper bag for ten minutes, then open it and smell immediately: the odour is strong, sweet and aromatic, dense and slightly cloying, and it is the scent behind the English name. It becomes far more powerful as the specimen dries, and a dried collection will perfume an entire storage box for months. No other large pale milkcap of wet acid ground smells like this.

Taking a spore print

Choose a mature cap, cut the stipe flush and set the cap gills down on white card. Because the deposit is pale, place a strip of black card alongside so the colour can be judged both ways. Cover the cap to keep humidity in and allow four to six hours; this species prints slowly.

The deposit is pale cream to buff with a faint yellowish tone, distinctly not white and distinctly not ochre-orange. Scrape it into a small heap before judging. Under a microscope the spores are broadly ellipsoid, roughly 7 to 9 by 5.5 to 6.5 microns, and ornamented with an incomplete network of ridges and warts that turns blue-black in Melzer's reagent, the standard Russulaceae pattern.

Substrate and season

The fungus is ectomycorrhizal, and in the field its partners are birch, spruce and pine growing on wet acid peat. Sphagnum bogs, boggy plantation rides, damp heathland with scattered birch and peaty upland woodland are all typical. It is essentially absent from dry, base-rich or disturbed ground. The season runs from late summer through autumn, peaking after prolonged rain.

Separating it from look-alikes

Lactarius glyciosmus is far smaller, at 2 to 5 cm, with a greyish lilac to pale drab cap, genuinely white latex and a sweet coconut-like scent. Size alone usually settles it.

Lactarius rufus is dark brick to red-brown, usually with a sharp central umbo, and produces copious unchanging white latex. It shares the acid habitat but shares neither the pale colour nor the aromatic smell.

Lactarius mammosus and its allies are small, dark grey-brown, umbonate and coconut scented, again separated by size and colour.

Lactarius flexuosus has a greyish lilac zoned cap, very distant gills and copious white latex.

Lactarius trivialis is larger and greyish violet, but it is greasy to slimy when moist and its latex is white and copious.

Paxillus involutus grows in the same birch bogs and is often confused at a distance. Its gills are soft, strongly decurrent, easily rubbed away from the cap flesh with a thumb, and they bruise rusty brown, and its spore print is snuff brown. There is no latex and no brittle granular flesh, so a single cut separates them.