From suillus - pertaining to swine
A distinctive Bolete with a red network around the stem which helps to distinguish it from other similar species. The base of the stem also turns blue when Melzer's Reagent is applied. Two colour forms are recognised, a red-capped form (var. rubriceps) and a yellow-capped form (f. lupinus) and some authors note others forms too.
Summer to Autumn.
Habitat & Distribution
Found with Oak, Beech and Lime, usually on calcareous soils, though it also grows on with Common Rock-rose (Helianthemum nummularium) on the Great Orme.
Said to be edible when cooked, but known to cause gaustric upsets in a relatively high proportion of people, for that reason it is one to avoid.
10.5–15.5 x 4.5–7µm, broadly elliptical to subfusiform.
Spore Print Colour
The red network around the stem makes it relatively easy to identify to other similar sized boletes which turn blue.
The Scarletina Bolete (Neoboletus luridiformis) does not have a red network around the stem, it is made of small 'dots' and is usually a deeper red with a darker brown cap.
The Deceiving Bolete (Suillellus queletii) could be confused for this species but that does not have red reticulated network around the stem either.