The Iodine Bolete (Hemileccinum impolitum) is a chunky bolete best known by its smell. Cut or break the base of the stem and you will notice a whiff of iodine or hospital antiseptic, strongest in older specimens. The cap is greyish-brown to yellowish-brown and finely velvety when young, becoming fibrous with age, and the small pores are bright yellow. The pale yellow stem has no net pattern and is finely scurfy, with rusty stains beneath the surface.
It grows with oak and other broadleaf trees, especially on calcareous soils in the southern counties, from June into November. Older books call it Boletus impolitus or Xerocomus impolitus.
Red-pored boletes such as the Lurid Bolete (Suillellus luridus) turn blue when cut, and the bitter Rooting Bolete (Caloboletus radicans) has a net pattern on its stem. Neither has the iodine smell.
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Distribution
Widespread and common in the southern counties
Habitat
On calcareous soils with deciduous trees, in particular Quercus
Etymology
Hemileccinum means 'half Leccinum', from the Greek hemi, 'half', because its scurfy stem resembles those of the Leccinum boletes. impolitum is Latin for 'unpolished', after the dull, felty cap.
Associates
Quercus
Cap
Domed at first, then convex to flattened, 5-12 cm across. The surface is velvety when young and more fibrillose with age, in greyish-brown to yellowish-brown tones, becoming smoother and dry.
| Colour | |
|---|---|
| Shape | Convex, Flattened |
| Surface | Fibrillose |
| Width | 5 - 12 cm |
Pores
Small and bright yellow, darkening with age and barely changing when bruised.
| Colour | |
|---|---|
| Size | small |
Tubes
| Colour |
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Flesh
Pale bright yellow and firm, changing little when cut.
| Colour | |
|---|---|
| Odour | Iodoform in the cut flesh especially near base |
| Taste | Mild |
Stem
Some rust-brown stains below surface
| Colour | |
|---|---|
| Texture | Fluccose |
| Shape | Clavate, Cylindric |
Spores
| Colour | |
|---|---|
| Shape | Subfusiform |
| Ornamentation | Smooth |
| Size | 9-16 x 4.5-6 μm |
Classification
- ↳ Phylum: Basidiomycota
- ↳ Subphylum: Agaricomycotina
- ↳ Class: Agaricomycetes
- ↳ Subclass: Agaricomycetidae
- ↳ Order: Boletales
- ↳ Family: Boletaceae
- ↳ Genus: Hemileccinum
Synonyms
- Boletus impolitus Fr.
- Boletus suspectus Krombh.
- Xerocomus impolitus (Fr.) Quel.
Reference Sources
G. Kibby (2017) British Boletes with keys to species. Geoffrey Kibby.
T. Læssøe, J. H. Peterson (2019) Fungi of Temperate Europe Vol. 1. Princeton University Press.
G. Kibby (2020) Mushrooms and Toadstools of Britain & Europe Vol. 1. Geoffrey Kibby.
Genus Hemileccinum
No other species found in this genus.
