Graceful Bolete Identification Guide

A Bolete Built Like a Wine Glass

Most boletes are stout: a thick stipe, a heavy cap, low centre of gravity. Austroboletus gracilis is the opposite. You come across it on a mossy bank in hemlock or spruce woodland, often in sphagnum or on the mossy top of a rotting log, and what registers first is stature - a long, slim, slightly curved stipe holding a comparatively small dark chestnut cap well clear of the moss. The proportions look almost delicate, and the species name is a fair description of the impression.

The setting reinforces it. This is a mushroom of acidic, humus-rich, mossy ground: conifer plantations, boggy hollows, cut banks along trails, mixed woods where oak grows alongside hemlock. Fruit bodies are usually solitary or scattered, not in troops or clusters.

Reading the Cap

The cap is 3-9 cm across, hemispherical when young and expanding to broadly convex, only rarely becoming flat. The surface is dry and dull, minutely velvety or finely tomentose when fresh, and it often becomes smoother with age or cracks into fine shallow tiles in dry weather.

Colour is a rich dark brown: chestnut, reddish-brown, chocolate, tawny or deep cinnamon, occasionally with a paler margin. Look also at the very edge - in this genus a narrow band of sterile tissue tends to overhang the pore layer slightly, giving the margin a fine lipped or fringed appearance under a lens.

The Pore Surface

Turn the cap over and read the tube layer carefully, because it holds the two best characters.

Colour and its progression. In young fruit bodies the pore surface is white to pale grey. As the spores mature it shifts through pale pinkish-buff to a distinct flesh-pink or vinaceous pink. Catching this transition is the fastest way to place the mushroom in the pink-spored bolete camp rather than among the olive-pored majority.

Reaction to touch. Press the pore surface firmly with a thumb and wait a minute. In Austroboletus gracilis there is no blue, no green and no rapid darkening; at most a slow, dull brownish discolouration. Any prompt blueing rules the species out immediately.

The pores themselves are small and round, roughly two or three per millimetre, and the tubes are up to about 1.5 cm deep and depressed in a ring around the stipe apex.

Stipe and Base

The stipe is the signature: 6-15 cm long but only 0.6-1.5 cm thick, tapering upward from a thicker, often somewhat rooting base, and frequently curved where it has grown up through moss. Colour is whitish to pale brown with pinkish, ochre or reddish flushes, generally paler than the cap.

The surface repays a lens. In the typical form it is finely roughened - pruinose, punctate, or longitudinally furrowed and pitted, sometimes with a shallow net-like pattern developing toward the base. There are no dark scabers, no true coarse raised reticulum standing proud like a fishnet, and no ring. Some collections (often treated as a smooth-stemmed variety) have a nearly polished stipe, so treat surface texture as supporting rather than defining.

Flesh and Colour Change

Split the fruit body lengthwise. The flesh is white and rather soft, and its most important quality is what it does not do: it stays white. No blue, no red, no grey, no blackening, even after several minutes. The stipe flesh may be very faintly brownish in the base.

That combination - dark velvety cap, pink pores, slender rooting stipe, unchanging white flesh - is close to a complete identification on its own.

Taking and Reading the Spore Print

Cut the cap free, lay it pore-side down on white card, cover it and leave it several hours or overnight. The deposit is reddish-brown, vinaceous or purplish-brown rather than the olive-brown typical of most boletes.

Microscopically the spores are large - roughly 11-17 by 5.5-8 micrometres - ellipsoid to fusiform, and, uniquely useful here, distinctly ornamented: pitted, warted or roughened rather than smooth. Smooth spores in a pink-pored slender bolete point to Tylopilus instead, so this is the character that formally defines the genus.

Substrate, Season and Ecology

Austroboletus gracilis is ectomycorrhizal, forming root sheaths with conifers - hemlock especially, also spruce and pine - and with oak in mixed stands. It is strongly tied to acidic, humus-rich, mossy ground, and moss is such a consistent companion that a search image of dark cap over green sphagnum works well.

Fruiting runs from midsummer into autumn, following prolonged wet weather. Fruit bodies emerge singly or a few at a time, are relatively long-lasting for a bolete, and frequently appear along shaded banks and the edges of trails where mossy soil is exposed.

Separating the Look-alikes on Morphology Alone

• Tylopilus felleus. Also develops pink pores, but the build is entirely different: a stout, thick stipe carrying a coarse, dark brown raised net over a paler ground, a pale buff to brown cap, and a pore surface that stains brown when handled. Stature alone usually settles it.
• Tylopilus plumbeoviolaceus and relatives. Young fruit bodies are washed with violet or purple on cap and stipe, the stipe is much thicker, and the spores are smooth.
• Leccinum species. Similar slender profile in some species, but the stipe is covered with dark tufted scabers, the pores are whitish to olive rather than pink, and the cut flesh usually discolours grey, vinaceous or black.
• Strobilomyces. Shaggy grey-black overlapping scales on cap and stipe, flesh reddening then blackening, and a black spore print.
• Austroboletus betula. Same genus and stature, but the cap is orange-yellow and sticky and the stipe carries deep, coarse, ladder-like ridges and pits.
• Porphyrellus species. Dark brown throughout with brown pore surfaces that stain blue-green and then black.
• Typical Boletus, Xerocomellus and Baorangia. Yellow to olive pore surfaces, olive-brown prints, and in many cases immediate blueing when cut.