Chrome-footed Bolete Identification Guide

The First Impression

Late summer, mixed woodland with oak, birch and hemlock, damp mossy ground. Something pink catches your eye in the leaf litter — a bolete with a soft rose to pinkish cap, matte rather than shiny, on a tall, slim, white stem. Pink-capped boletes are not rare, so at that point you are only partway there. What finishes the job is at the other end: brush the litter away from the bottom of the stem and it is washed a startling chrome- or lemon-yellow, as though it had been dipped in paint. That yellow foot, the pink cap and pink stem ornament together are unique among boletes, and once you have seen the combination you can name Harrya chromapes at a glance for the rest of your life.

Reading the Cap

Size and shape. Usually 4 to 12 cm across. Rounded and firmly convex when young, expanding to broadly convex and eventually nearly flat, occasionally becoming slightly uneven or lumpy.

Colour. Rose-pink to pinkish-red or purplish-pink when young and fresh, often deepest at the centre. It fades markedly with age, sun and rain to pinkish-tan, buff, dull brownish-pink and finally almost dingy ochre. Faded specimens are much harder to name from the cap alone, which is why the stem base matters so much.

Surface. Dry to slightly tacky in wet weather, matte and very finely tomentose or velvety when young, smoothing with age. In dry conditions the cuticle can crack a little at the disc. It is never glutinous.

Margin. Even, sometimes overhanging the pore surface slightly when young, and occasionally hung with fine cuticular fringe.

The Pore Surface

Turn the cap over. The tubes are 8 to 15 mm deep, and the pore mouths are small and round to slightly angular.

Colour. White to pale cream when young, becoming pale pink to pinkish-buff or flesh-brown as the spores mature and dust the surface. The pink of the pores is spore colour showing through, so young buttons show none of it.

Attachment. Adnate and typically depressed around the stem apex.

Bruising. Press the pores hard and wait. There is essentially no reaction, at most a faint brownish stain in old material. No blue, no green, no rapid darkening.

The Stipe and Base — The Key Structure

The stem is the best part of this species and repays close reading. It is 5 to 12 cm long and 1 to 2.5 cm thick, often distinctly long relative to the cap, tapering upwards or more or less equal, and firm.

Ground colour. White to whitish, sometimes with a pinkish flush in the upper part.

Ornamentation. The upper two-thirds is covered in small, roughened, fibrillose points — scabers, of the kind found in Leccinum — but coloured pink to rose or reddish rather than brown or black. Under a hand lens they resolve into tufts of coloured fibrils, dense near the top and thinning downwards. Pink scabers are rare enough to be diagnostic on their own.

The chrome-yellow base. The bottom quarter to third of the stem is flushed a bright chrome-yellow, lemon or golden-yellow. Crucially, the yellow is not just a surface stain: split the stem lengthwise and the yellow runs into the basal flesh, and the mycelial threads binding soil at the very bottom are yellow too. Always excavate the whole base; if you snap the stem above ground you may leave the diagnostic character in the soil.

No ring and no net. There is no partial veil, no ring and no reticulation.

Flesh and Colour Change

Slice the fruiting body from cap to base in one cut. The flesh is white and firm in the cap and upper stem, soft-fibrous, and it is bright yellow in the base as described. Watch the exposed surface for several minutes: cap flesh stays white or takes on only a faint pinkish or greyish tinge, and the yellow base holds its colour. There is no blueing anywhere. The odour is mild.

Taking a Spore Print

Cut the stem off level with the tubes, place the cap pore-side down on white paper, cover it, and leave it four to eight hours or overnight.

The deposit is pinkish-brown, flesh-brown or vinaceous-brown — a warm pinkish tone, quite distinct from the olive-brown of most boletes and from the yellow of Gyroporus. That print colour is why the pore surface flushes pink with age. Under the microscope the spores are smooth, thin-walled and narrowly ellipsoid to subfusiform, long for their width at roughly 11 to 17 by 4 to 5.5 micrometres.

Substrate and Season

Harrya chromapes is ectomycorrhizal and turns up in mixed and broadleaved woodland with oak, birch, beech, and often hemlock and pine in the eastern North American forests where it is commonest; it also occurs in eastern Asia. It fruits on soil, in moss, litter or thin humus, singly or in scattered small groups, from midsummer through to early autumn, often on damp, shaded slopes and along stream banks. It has no association with wood.

Separating It From Look-Alikes on Morphology Alone

Leccinum species. Share the scabrous stem, which is the main source of confusion. Their scabers are brown, grey or black, never pink, their caps are brown, orange or white rather than rose-pink, their stem bases are white to greenish or bluish but not chrome-yellow, and most stain the cut flesh grey, vinaceous or blackish within minutes. The yellow foot plus pink scabers resolves it every time.

Tylopilus felleus. Also has pinkish pores at maturity and a pinkish-brown spore print, but its cap is tan to warm brown, its stem is stout and covered with a coarse dark brown net rather than scabers, and there is no yellow base.

Tylopilus rubrobrunneus and relatives. Larger, with purple-brown to maroon-brown caps, smooth stems, pink pores and a brown print. No pink scabers, no yellow foot.

Retiboletus and other yellow-stemmed boletes. May show yellow in the stem flesh, but they carry a raised network on the stem and drop olive-brown prints.

Boletus, Baorangia and Suillellus relatives. Reticulate or smooth stems, yellow or red pores, frequent blueing, olive-brown prints.

Austroboletus and Aureoboletus species. Some have pinkish tones and a pinkish print, but their stems are ridged, pitted or viscid, never pink-scabrous with a yellow base.

A Field Sequence That Works

1. Note the setting: soil in mixed or broadleaved woods, midsummer to early autumn.
2. Look for a matte, dry, rose-pink cap, allowing for fading.
3. Check the pores: white then pink-tinged, no blueing.
4. Hand-lens the stem for pink scabers.
5. Excavate the base and confirm chrome-yellow inside and out, plus yellow mycelium.
6. Take a print and confirm pinkish- to vinaceous-brown.