Bloody Milkcap | Lactarius sanguifluus Identification Guide

The Setting and the First Look

You will be under pine on lightish, often calcareous soil, in the kind of open, needle-strewn woodland where moss and thin grass grow between the trunks. Warm southern and Mediterranean pine woods are the heartland, and the fungus appears in autumn, often in loose troops of several fruit bodies pushing up through the needle litter with their caps still half buried. First impressions are of a heavy, solid, funnel-shaped fungus in muted colours: dull ochre, buff-orange, greyish-pink or faintly vinaceous, sometimes with dirty green blotches, and a short, thick stem. It looks chunky and rather dull until you cut it, at which point the whole identification resolves in seconds.

Reading the Cap

The cap is 5 to 12 cm across, occasionally larger. It begins convex with a strongly inrolled margin, then flattens, becomes centrally depressed and finally funnel-shaped, with the margin often staying inrolled and wavy well into maturity. The surface is smooth and slightly sticky when wet, drying matt, and it commonly picks up needles and soil grains. Colour is the point that gives most people trouble because it is not vivid: expect ochre-buff, pale brick, greyish-orange or a washed pinkish-vinaceous, frequently with paler and darker patches. Concentric zoning may be faint or absent altogether, which is a useful contrast with some relatives that are boldly banded. As the fruit body ages, irregular dull green to verdigris blotches develop, especially where the cap has been damaged or where slugs have grazed.

The Gills and the Juice

Gills are the heart of this identification. They are crowded, narrow, adnate to clearly decurrent so that they run some way down the stem, and they fork repeatedly near the stem apex. Fresh colour is a pinkish-ochre, salmon or vinaceous-buff, distinctly duller and more pink-toned than the bright carrot-orange gills of some relatives.

Now cut across them with a clean blade and watch closely for a full minute. Milk appears at once, and in this species it is a deep blood-red to dark wine-red or purplish-red from the very first instant. It does not begin orange. It does not need time to change. That immediacy is the diagnostic feature, and it is why the milk test must be done on a fresh, well-hydrated specimen and observed from the moment the knife passes. Over the following minutes the exposed juice dulls to a darker purplish-brown, and the cut gill tissue slowly develops green stains, but it never turns bright orange at any stage. Dry weather can suppress the milk to a mere film, so cut two or three specimens if the first is stingy.

The Stem and the Base

The stem is short and stout in proportion to the cap, roughly 3 to 6 cm long and 1.5 to 3 cm thick, cylindrical or narrowing downward, firm at first and becoming hollow with age. The surface is whitish-pink to vinaceous with a fine bloom, and in most collections it carries scrobicules: shallow, rounded, slightly sunken pits a few millimetres across, coloured deeper orange, vinaceous or reddish than the background. Wipe the soil off and hold the stem to the light to see them. The base is often tapered and may show green discolouration where it was in contact with damp litter. There is no ring and no volva.

Flesh and Colour Change

Slice the fruit body lengthwise. The flesh is firm, brittle in the cap and rather granular, pale buff to whitish with vinaceous tones under the cap skin. Within a minute or two of cutting, the exposed flesh flushes wine-red as the juice spreads through it, and over a longer period, tens of minutes to hours, the cut face and any bruised areas develop the dull green tone that follows all fruit bodies of this group. Watching the whole sequence, immediate dark red followed by slow greening, is more informative than any single glance.

Taking a Spore Print

Remove the cap and set it gills-down on white paper or glass, cover it, and leave it for four to eight hours. Because the gills are decurrent, prop the cap on a small support so air can circulate. The deposit is pale ochre to buff-cream with a slight yellowish cast, not white and not deep rusty. Judge the colour on a thick deposit in daylight. Under the microscope the spores are broadly ellipsoid and ornamented with warts and ridges forming a partial network, and they are amyloid in Melzer's iodine, staining blue-grey.

Substrate, Season and Ecology

This is an ectomycorrhizal partner of pine, sheathing the fine roots and exchanging mineral nutrients and water for sugars. It therefore grows from soil and never from wood, dung or compost, and its presence means a pine is close by. Calcareous and neutral soils in warm, dry regions suit it best, and it is much commoner in southern Europe and around the Mediterranean than in cool northern forests. The season is autumn, typically from the first substantial rains after the summer drought through to the first hard frosts, with fruiting arriving in flushes a week or so after rainfall. Productive stands repeat annually because the mycelium is long-lived and tied to the same root systems.

Separating the Saffron Milkcaps on Morphology

All members of this group have decurrent gills, scrobiculate stems and juice that eventually greens, so the milk colour and its timing carry the work.

• The Saffron Milkcap, the best-known member of the group, is the standard comparison. Its cap is a clear carrot-orange with obvious concentric zones, its gills are bright orange, and its milk is carrot-orange and stays orange, only slowly turning dull greenish. It is a pine associate too, so colour is the separator, not habitat.
• Lactarius semisanguifluus also grows with pine and begins with orange milk, but that milk turns wine-red within roughly one to two minutes. If you did not watch the cut from the very first second, this species is the one most easily confused; the greening of its cap is usually strong and rapid.
• Lactarius deterrimus is the spruce species. Its cap is orange with a green flush developing early, the milk is orange and turns wine-red after a longer delay of ten to thirty minutes, and its host tree is the giveaway.
• Lactarius vinosus, treated by some as very close to the present species, has a distinctly darker vinaceous to purple-brown cap and equally dark red milk, and its gills are more strongly wine-tinged.
• Lactarius salmonicolor and Lactarius quieticolor sit with fir and pine respectively, with salmon to orange milk that does not go dark red immediately.
• Any milkcap outside this group with white, cream or yellowing juice, or with no greening at all, is not a candidate.

Field Checklist

Under pine on lightish soil in autumn; a stout, funnel-shaped, dull ochre to greyish-pink cap with weak or absent zoning; crowded, forking, decurrent pinkish-ochre gills; a short stem with coloured pits; dark blood-red milk from the instant of cutting; slow green staining afterwards; and a pale ochre spore print.