#5 Strange Stinkhorns

It could be the pink wrinkled paw of a weird and unknown creature hatching from an egg in an ancient forest, but it's just a fungus in a garden.....

Local parks, reserves and botanic gardens can be excellent places to observe nature up close. The four stinkhorn fungi that I am featuring here were all photographed at the Hunter Region Botanic Gardens at Heatherbrae on the Pacific Highway north of Newcastle.

What are stinkhorns?

Stinkhorn fungi belong to the Clathraceae family. Most have an absurd eye-catching appearance that varies from phallic-shaped or tentacled, basket-shaped to draped in delicate lacy skirts. But all have two common features: they emerge from a terrestrial egg-like structure, and they produce a foul smelling sticky spore mass.

Aseroe rubra with its spore-coated red tentacles emerging from an egg-like sac

The spherical or flattened glutinous egg forms on or just below the ground surface, and if dissected reveals a fully developed compressed fruiting body awaiting the right conditions to emerge and mature. The image above shows the Starfish Stinkhorn, Aseroe rubra, emerged from the ruptured 'egg'.

Starfish or Anemone Fungus, Aseroe rubra, is found in Australia's eastern states in moist mulched gardens as well as alpine grasslands and mountain woodlands. As far as I am aware, it is not found in the west, but if residents of the western and dry inland parts of Australia have seen this growing in their areas I'd be interested to hear about it.

There are more pictures and observations of Aseroe rubra at my Australian Fung Blog.

A Starfish Fungus with its hollow stalk, divided arms and brown spore mass

My first sighting of the Starfish Fungus was in the moist rainforest of Barrington Tops National Park east of the Hunter Valley, but since then I have found several, and often massed displays, at the Hunter Region Botanic Gardens. The preferred habitat of many stinkhorns is mulched gardens, so therefore they can make regular appearances in home gardens.

Reproduction

Stinkhorn fungi stink for a reason. Flies and other insects that are attracted to the smell of rotting flesh or faeces are drawn to the foul odour of the fungi. The odour emanates from a greenish-brown gooey substance (gleba) that contains spores. Visiting insects find this slime delectable and trample in it as they feast, then unwittingly spread the fungus spores enabling the stinkhorn life-cycle to continue elsewhere.

Phallus rubicundus is a common stinkhorn popping up in mulched gardens and rainforest humus

Phallic-looking fruiting bodies emerge from egg-like sacs and can elongate several inches within a period of a few hours, making these striking and almost obscene growths a novelty in suburban gardens and lawns. The novelty soon wears off, however, as the pong of the fungi reaches the kitchen window. But I will admit that my olfactory glands were not offended and I think their unsavoury reputation is somewhat exaggerated.

But as odd and repugnant as they might appear, they will do no harm to your garden and will wilt and decay within a very short period of time.

Note in the Phallus rubicundus image above the stem is perforated and hollow. It resembles the texture of foam rubber. The conical cap coated in a sticky spore mass is separated from the stem, joined only at the summit. This separated cap is an important feature in identifying it from similar phallic stinkhorns.

Lantern Fungus

I have only encountered one flurry of Lantern Fungi, Lysurus mokusin, at the Hunter Region Botanic Gardens. The tip of the pinkish-orange stalk is branched into 4 to 6 short arms which often remain joined. The number of arms corresponds with the number of angular ribs on the stalk and the gooey brown spore mass is concentrated in the vertical depressions between the arms.

An aging Lantern Stinkhorn with spreading arms

Mutinus borneensis is a white stinkhorn, narrower than the previous two orange phallic fungi I've illustrated here. On emerging from the small glutinous sac, it also elongates at a remarkable rate, attracting flies to the orange-brown pointed tip coated in brown spore bearing gleba.

Egg-like sacs of Mutinus borneensis generally make a massed display

Wood chips and organic matter provide ideal habitat for stinkhorn fungi, so mulched gardens and local parks are likely to support occasional outbreaks of these strange but fascinating growths. Observe them if you have the opportunity. In some parts of the world it is reputed that these jelly eggs and spongy fetid fungi end up on the dinner table, but not in this household!

Digging them out or poisoning them will not rid your garden of these odd creations. They will be fleeting, so enjoy their brief existence.

Via my blog counter, I notice that there are many international visitors to this page on some of Australia's interesting stinkhorn fungi. I would be most interested to know if my pictures and observations have helped others identify stinkhorns from other countries. If readers feel inclined to leave a brief message via the 'comments' tag below or my email contact on the right of the page, I would be most appreciative.