Painted Suillus Identification Guide

First Impressions and the Setting

Look for Painted Suillus wherever eastern white pine grows - old plantations, mixed pine-hardwood slopes, mossy roadside banks under big white pines, and pine-needle carpets in parks and cemeteries. The species is bound to five-needle pines, so the tree is effectively part of the identification, and the first thing to do on finding a candidate is to look up and count needles in a bundle. The mushroom itself is unmistakable at a glance in fresh condition: a dry, shaggy cap covered in brick-red to rosy-red woolly scales over a yellow ground, sitting on a stalk that is equally scaly and red below a woolly ring. Young caps look almost entirely red; older ones look like a red net stretched over yellow, because the expanding cap pulls the scales apart and the yellow flesh shows through the gaps.

Reading the Cap

The cap is 3-12 cm across, convex and later broadly convex to flat. Its surface is dry, never slimy or sticky, and this matters because so many relatives in the genus have glutinous caps. Covering it is a dense coat of coarse fibrillose scales and woolly tufts in brick-red, rosy-red or reddish-brown, laid over a yellow to orange-yellow ground layer. As the cap expands the scale coat cracks into patches with yellow showing between them, and in rain and age the red fades to tawny, buff or brownish. Check the cap margin: it usually carries hanging remnants of a greyish-white to buff partial veil, sometimes as a continuous fringe, sometimes as scattered tatters.

The Pore Surface

Turn it over and study the tubes carefully, because they are as distinctive as the cap. The pores are bright to dull yellow when young, ageing dingy yellow-brown, ochre or brownish. They are large - noticeably larger than the pinprick pores of many boletes - conspicuously angular, and arranged in radiating rows so the surface looks divided into elongated compartments running outward from the stalk. The tube layer is adnate to somewhat decurrent, extending a short way down the stalk. Press firmly and wait: bruised pores stain brown to reddish-brown or dull cinnamon, developing over a minute or two rather than instantly.

Stalk, Ring and Base

The stalk is 4-12 cm long and fairly stout, and it has two zones separated by a ring. Above the ring it is yellow and finely mealy or nearly bald; below it, it is clothed in the same red to reddish-brown fibrils and scales as the cap. The ring itself is a woolly, cottony, greyish-white to buff band that is often ragged and may collapse into a fibrillose zone in older specimens; on the underside it can be darkened by fallen spores. Look for glandular dots - the sticky dark speckles typical of many Suillus stalks - and note their relative absence here, the surface being scaly instead. The base is often bound with white to pale yellow mycelium and pine litter.

Flesh and Colour Change

Split the mushroom in half from cap to base with a clean cut and watch the exposed surface for several minutes. The flesh is yellow throughout, paler in the cap and deeper towards the stalk base. On exposure it slowly stains pinkish-brown to reddish-brown or vinaceous-brown, especially in the stalk and around insect damage. There is no blue reaction. The flesh is soft and easily broken, and the tube layer separates from the cap flesh readily, as in the genus generally.

Taking a Spore Print

Cut the stalk off flush with the tube layer and rest the cap pore-side down on white paper under a cup or bowl for six to twelve hours. The print is olive-brown to dull cinnamon-brown - a warm brown with an olive cast, distinctly darker and browner than the pale yellowish print of a chanterelle and quite different from any white-spored gilled mushroom. Under a microscope the spores are smooth and elongate-elliptical, in the range typical for the genus. In the field you can often see the same colour smeared on the ring underside and on caps beneath a mature specimen.

Substrate, Season and Ecology

Painted Suillus is ectomycorrhizal, and its partnership is narrow: eastern white pine and other five-needle pines. It fruits from soil, moss and needle duff beneath those trees, singly, scattered or in troops, and often in the same spots year after year. The season is summer into autumn, following warm rain, and fruiting can continue late in mild years. Because the association is so tight, the presence of the right pine is strong supporting evidence, and its absence should make you reconsider. It does not fruit from wood, stumps or chips.

Separating the Look-alikes on Morphology Alone

• Suillus lakei: closely similar, with a dry reddish-scaly cap, but it partners with Douglas-fir in western North America, has a less well-developed ring, and the flesh in the stalk base frequently flushes blue-green when cut.
• Suillus americanus: shares the white pine habitat but has a slimy to sticky yellow cap with only scattered reddish fibrils or patches, a thin flesh, a much less substantial ring, and yellow angular pores on a slender stalk with conspicuous glandular dots.
• Suillus cavipes: has a dry brownish-tawny woolly cap and grows with larch, and decisively its stalk is hollow when split lengthwise.
• Suillus grevillei and other larch associates: have smooth, viscid, bright yellow to reddish caps with no shaggy scale coat.
• Chalciporus piperatus: much smaller and more slender, with a smooth tawny cap and pores that are reddish to rusty-brown rather than yellow.
• Tricholomopsis rutilans: an easy confusion at a distance, being a red-scaly cap over yellow, but it has gills rather than tubes and it grows on conifer wood and stumps.
• Faded old Painted Suillus loses its red and can be mistaken for a plain brown Suillus; check the stalk below the ring, where scale remnants and reddish fibrils usually survive longest.

Working Checklist

Dry cap with brick-red woolly scales over yellow; veil fringe on the margin; large angular radiating yellow pores staining brown; woolly ring with a red-scaly stalk below and yellow above; yellow flesh slowly turning reddish-brown; olive-brown spore print; on soil under eastern white pine.