Lantern Stinkhorn
Lysurus mokusin
Also called ribbed lizard claw, small lizard's claw, fluted stinkhorn
Recognisable by its distinctly ribbed, angular stalk that ends in a cluster of short arms fused into a lantern-like point, with dark spore slime on the inner arm faces.
Overview
The Lantern Stinkhorn is unusual among stinkhorns for having a stalk that is not round in cross section. Instead the column is sharply fluted, with four to six longitudinal ridges and grooves running its full length, so a slice looks star-shaped or polygonal rather than circular.
At the summit sits a short crown of arms, equal in number to the flutes and continuous with them. When the fruiting body first expands, these arms remain pressed together into a tapering, lantern- or pagoda-like point; later they may separate and curve outward slightly, but they never become the long spreading rays of Clathrus archeri.
Lysurus is a genus of the family Phallaceae with a mainly warm-temperate and subtropical distribution. L. mokusin is native to eastern Asia and has spread through horticultural trade into North America, Europe and Australasia, where it usually appears in garden mulch and other disturbed, enriched ground.
How to identify it
Stalk
The stalk is 4–12 cm tall and 1–2.5 cm thick, hollow, spongy and chambered, and distinctly angled: four to six longitudinal ridges give it a fluted, celery-stalk profile. Colour is whitish at the base grading to pink, salmon or reddish upward. The base sits in a whitish, membranous volva with a white cord attached below.
Arms
Four to six short arms, each 1–3 cm long, crown the stalk. They continue the line of the flutes, are pinkish to red, and are initially joined at their tips into a pointed lantern shape; with age they part and spread modestly.
Gleba and flesh
Dark olive-brown to blackish slime coats the inner surfaces of the arms and the very top of the stalk, so the crown appears dark against the pink column. The tissue is soft, water-filled and honeycombed, and the whole fruiting body wilts within a day or two. The egg stage is a whitish to greyish ball 2–4 cm across with a gelatinous inner layer.
Where and when it grows
It fruits in nutrient-rich, disturbed ground: wood chip mulch, bark beds, compost heaps, vegetable plots, nursery containers, greenhouse soil and lawn edges with buried organic matter. It rarely appears deep in undisturbed woodland.
The season runs from early summer through autumn, with flushes after warm rain. Native to China, Japan and neighbouring parts of eastern Asia, it is now recorded from the Pacific coast and southeastern United States, parts of Europe, Australia and elsewhere, almost always in gardens and landscaped ground.
Ecological role
The species is saprobic, decomposing bark, wood chips and other plant residues. Pale rhizomorphs run through the substrate and produce eggs at the surface, often several at once in a mulched bed.
Spore dispersal follows the standard stinkhorn strategy: a fetid, sugar-rich slime attracts flies and beetles, which feed at the arm crown and carry spores off. The compact lantern of arms concentrates the gleba in one place at the top of a tall stalk, lifting it above the mulch surface where insects can find it easily.
Similar species
Lysurus cruciatus is very similar in silhouette but its stalk is round in cross section and not fluted, and its arms tend to separate and curl outward more freely. Lysurus periphragmoides has a smooth cylindrical stalk topped by a globose lattice rather than a few discrete arms.
Pseudocolus fusiformis has three or four long tapering arms fused at the apex above a short, unfluted stalk, giving a much larger arm-to-stalk ratio. Mutinus species are simple unbranched spikes with no arms at all, and Phallus species carry a single hanging thimble-shaped cap. The fluted, angular stalk is the single most reliable field character for L. mokusin.