Phallus hadriani - Dune Stinkhorn

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Phallales

Phallus hadriani, the Dune Stinkhorn, emerges from an 'egg' beneath the surface. The cap is initially covered with olive-green 'gleba', a smelly coating that attracts insects which in turn distribute the spores. In Britain this is a rare species and almost exclusively restricted to sand dunes. A violet volva distinguishes the Dune Stinkhorn from the much more common Stinkhorn, Phallus impudicus, which has a white volva but in other macroscopic characteristics is much the same.

The Dune Stinkhorn shown here was photographed by Nathan Wilson with whose kind permission it is shown here and in Pat O'Reilly's new book Fascinated by Fungi, published by First Nature in September 2011.

Identification Guide

Description	Beneath the sticky olive-green gleba coating, the cap of the Dune Stinkhorn has a raised honeycomb structure. This is all that many people ever see of the cap of this fungus because insects very quickly eat the spore-bearing gleba, at the same time getting some of it stuck to their legs so that spores are transported over quite large distances as the insects fly off in search of food elsewhere. The stem is white and looks like expanded polystyrene, and it emerges from the remains of a violet-coloured universal veil that covered the fruitbody at the egg stage and ultimately remains around the base of the stem like a bag.
Dimensions	Typically 10 to 18cm tall; stipe diameter 2 to 3.5cm; cap 2.5 to 4.5cm across.
Other features	The 'egg' is typically 4 to 6cm in diameter, gradually becoming elongated until it ruptures and the stem emerges very quickly, bearing the gleba-coated cap aloft. At the egg stage this fungus is reportedly edible, but it is not greatly valued as a source of food (except, later on, by flies!).
Stem	The white stipe has a texture and appearance of expanded polystyrene; it persists for several days after the gleba has been consumed by insects.
Spores	The slimy gleba, which is dark olive, contains yellow spores.
Odour/taste	A strong, unpleasant odour; no distinctive taste.
Habitat	In Britain this stinkhorn is confined almost exclusively to sand dunes.
Season	June to October.
Occurrence	Rare.
Similar species	Phallus impudicus, the Stinkhorn, has a white volva and is on average somewhat taller.