Netted Stinkhorn

Phallus duplicatus is the common veiled stinkhorn of eastern North America and the temperate counterpart of the tropical Veiled Lady. It emerges from a buried whitish egg as a stout, hollow white stalk carrying a coarsely pitted, slime-covered head, and from beneath the head a white net-like veil drops a short distance — typically covering only the upper third to half of the stalk.

The species is often listed in older references as Dictyophora duplicata, from the days when veiled stinkhorns were segregated into their own genus. Modern classifications place it in Phallus alongside the veil-less species, since the presence of an indusium is a variable character within the group.

In the field the combination of a thick stalk, a strongly honeycombed head and a short, coarse-meshed skirt is diagnostic. Fruiting bodies are large — often approaching 20 cm tall — and appear in lawns, mulched beds and woodland margins with rich soil, usually in warm, wet weather and singly or in small groups.

Egg stage

A whitish to pale buff or pinkish egg 3–6 cm across, sitting partly buried in litter or soil and attached below by thick white rhizomorph cords. Sliced lengthwise it shows the gelatinous layers, the compressed stalk, the folded veil and the dark olive gleba over the head.

Stalk

Stout, white, hollow and spongy, 10–20 cm tall and 2–4 cm thick, with a coarsely chambered pitted wall. The base sits within a loose, sac-like white to pale volva, the remains of the egg.

Indusium

A white, net-like skirt hanging from beneath the head. Compared with Phallus indusiatus it is distinctly short, usually extending only a third to halfway down the stalk, and its meshes are coarser and more irregular. Sometimes it is partly collapsed or torn against the stalk.

Head

Bell- to thimble-shaped, 3–5 cm tall, its surface raised into a coarse honeycomb of ridges and pits and topped by a small white perforate disc. When fresh it is coated in dark olive to olive-brown sticky gleba; once insects have cleared this, the pale ridged network is clearly visible.

Spores

Spores lie in the gleba slime rather than being released as a dry print; they are minute, smooth and ellipsoid, and the deposit appears olive-brown.

This stinkhorn favours rich organic ground: garden soil, lawns and grassy areas over buried wood, leaf litter in deciduous woodland, mulched beds, woodland edges and clearings, and disturbed ground with plentiful decaying plant material. It commonly appears in suburban settings where mulch or old roots are present in the soil.

It is chiefly known from eastern and central North America, from southern Canada south through the eastern United States, with reports from eastern Asia and scattered records elsewhere. Fruiting occurs from summer into autumn, especially after warm, heavy rain, and individual fruiting bodies are short-lived, expanding overnight and collapsing within a day.

Phallus duplicatus is a saprotroph, decomposing buried wood, roots, leaf litter and other organic matter in soil. Its mycelium spreads as white cords through the litter and topsoil, forming eggs at intervals along them; when moisture and temperature are right the egg ruptures and the stalk inflates rapidly by expanding pre-formed chambers with water.

Dispersal is entomophilous. The liquefying gleba gives off a powerful odour that draws flies, beetles and other insects, which feed on the slime and pick up spores on their bodies. Spores survive passage through insect guts and are deposited on new substrate. The white veil probably enhances the visual attraction of the fruiting body and offers a foothold for arriving insects, much as the longer indusium does in tropical relatives.

Phallus indusiatus is separated by its much longer, finer-meshed veil, which often reaches most of the way down the stalk or spreads onto the ground, and by its tropical to subtropical, frequently bamboo-associated habitat. Phallus impudicus has the same pitted head and spongy white stalk but produces no veil at all.

Phallus ravenelii shares the North American range and rich-soil or wood-chip habitat but has a smooth to finely granular head rather than a coarse honeycomb, a usually pinkish-purple egg, and no indusium. Mutinus species are much slenderer and orange or pink, with the gleba applied directly to the tapering upper stalk and no distinct free head. Unexpanded eggs resemble puffballs from outside; a vertical cut showing the gelatinous layers, dark gleba band and folded net settles it.