Jack O’ Lantern Omphalotus illudens (Schwein.) Bresinsky & Besl (illustrated 50% life size) Cap 5–10cm across, strongly depressed to funnel-shaped; bright orange. Stem 40–140×7–28mm, wavy and tapering towards the base; paler than cap. Flesh yellowish, darkening towards the stem base; taste not distinctive, smell strong and unpleasant. Gills decurrent; golden to orange. Spores 5–7×4.5–6.5¼, subglobose. Spore print white. Habitat on the roots or at the base of trunks of certain trees, especially oak and chestnut in Britain; autumn. Very rare. Poisonous. Note this fungus may be seen to glow in the dark, the phosphorescence coming from the gills when the spores are mature. In my first book I listed it as Omphalotus olearius sensu auct. Brit., but this name is now reserved for the shorter-stemmed mushroom that is found in southern Europe, mainly on olive trees.