Ischnoderma benzoinum

(Wahlenb.) P. Karst.

Mature brackets on a fallen Scot’s pine stem near Windsor Great Park, Surrey.
Numerous brackets growing on the underside of a fallen pine stem at Kew Gardens, London
A senescent bracket that could be confused with Phaeolus schweinitzii
The irregular white pore surface and slotted tubes
The irregular pore surface bruising a light beige

Mature brackets on a fallen Scot’s pine stem near Windsor Great Park, Surrey.
Numerous brackets growing on the underside of a fallen pine stem at Kew Gardens, London
A senescent bracket that could be confused with Phaeolus schweinitzii
The irregular white pore surface and slotted tubes
The irregular pore surface bruising a light beige
Fruit bodies on a fallen pine in Windsor, UK.
Fruit bodies on a fallen pine in Windsor, UK.
Fruit bodies on a fallen pine in Windsor, UK.
Fruit bodies on a fallen pine in Windsor, UK.
Fruit bodies on a fallen pine in Windsor, UK.

Common name

Benzoin bracket.

Often found on

Fir, larch, pine, spruce.

Sometimes found on

Other conifers.

Location

Found growing at locations along the entire above-ground scaffold structure of the host tree. Persists on dead trees – often in great abundance.

Description

Annual. Soft and fleshy when young and becoming tough and woody. Bracket rimmed off-white. Upper surface emerges an orange-brown and blackens in maturity – can create a zoned appearance to growing brackets. Exudes reddish-brown water droplets. Pore surface white and ageing to a light beige-brown. Pores visible and irregular. Sometimes slotted. Found singularly or in abundance – small to relatively large (~15-20cm across).

Confused with

Fomitopsis betulina (white flesh); Ischnoderma resinosum (on deciduous trees); Phaeolus schweinitzii (confused only in senescence, breaks apart far more readily and has maze-like pores).

Significance

No research has been undertaken on the pathogenicity of this fungus. Attributed to a white rot of the wood. Presence indicative of localised dysfunction, on living trees. Where targets exist, hollowness investigations may be necessary. Presence along a stem in various places might indicate a coalesced decay column.