Saturday, October 26, 2013

Popping up like Mushrooms

Well, they are mushrooms. And according to George Barron, the author of Mushrooms of Ontario and Eastern Canada, under optimal conditions a Stinkhorn can expand from its nascent "egg" stage to full size within thirty minutes, an impressively fast rate of growth that certainly qualifies as "popping up".

While looking around for something interesting to photograph at the Tweed Heritage Center gardens, I noticed a smell like rotten carrion and wondered if perhaps a hapless mouse or chipmunk had perished and was decomposing in the late season flower beds. This was how I discovered some Ravenel's Stinkhorns (Phallus ravenelii) peeking out of the grass mulch and sawdust. Stinkhorns are often smelled before they are seen, an attribute that some find less than endearing.

As with other fungi, the purpose of the Stinkhorn's fruitbody is obviously reproduction. Gilled fungi and Boletes simply drop their microscopic spores through their gills or pores, to be wafted away on the slightest breeze. Some Bird's Nest Fungi actively eject their spore packages. Truffles play it safe and hide underground, but when they're good and ready to be fruitful and multiply, they produce an odor that induces animals to eat them and spread their spores via their feces. Perhaps strangest of all, before sporulation, the mycelium of Entomophthora muscae grows into the fly's brain, taking over its behavior and making it crawl to the highest available location to maximize spore dispersal.

Stinkhorns exploit flies, and presumably other insect species attracted to carrion, in a more benign fashion to pass along their genes to the next generation. The sticky, vile smelling sludge at the tip of a Stinkhorn not only contains sugary compounds – a combination of scent and taste that flies find irresistible – it also contains the Stinkhorn's spores, and as the flies crawl around enjoying their dinner the goo sticks to their feet and the insects convey the fungus' spores to new sites.

Compared to the 10 cm of the Ravenel's Stinkhorns in the photos above, this Skirted Stinkhorn (Phallus duplicatus, however, in my field guide it's named Dictyophora duplicata) is a giant. It stood out like a ... hmmm, let's say like a proverbial sore thumb, from the darker background of woodland floor debris. It was easily 20 cm in length and I've included my hand in the photo to impart a sense of scale.

Unfortunately this specimen is past its peak. The depressions in the morel-like tip are reservoirs for the Skirted Stinkhorn's viscid spore mass, which is long gone, but the fetid scent still lingers on and continues to attract flies. This species of Stinkhorn also sports a doily-like "skirt" around the base of the cap, the frayed remnants of which can be seen in the photos.

Also growing amidst the leaf litter along the trans-Canada Trail, only a few feet away from the Skirted Stinkhorn, was a lone Dog Stinkhorn (Mutinus caninus). And sure enough, where there are Stinkhorns, there are flies – note the mating pair in the background. Dog Stinkhorns attain a length of about 10 cm.

Stinkhorns not only pop up out of nowhere, they can vanish almost as quickly. The shelf life of the Ravenel's Stinkhorns was about three days after their prime (albeit they were pretty rough around the edges), but the Dog Stinkhorn in the image above – its goal of spreading the fungus' genes having been served – was little more than a gooey mass by the following morning.

With such a limited "best before" date one is lucky to stumble across opportunities to photograph these fascinating fungi, so I was thrilled when a few days later I encountered a colorful group of about a dozen Dog Stinkhorns. Or so I assumed at the time ... having done some more research, I now think these masses of malodorous mushrooms might be Elegant Stinkhorns (Mutinus elegans). The fruitbodies are longer (about 12 to 15 cm in length), there's no distinct separation of the spore mass and stalk, and more of the fruitbody – one third to one half – is covered in slime.

A student of the natural world soon learns that evolution and natural selection proceed according to their own rules, that life adapts as it must in order to survive and perpetuate itself and doesn't care about our human sensibilities ... nonetheless, I was holding my breath whilst taking these photographs.

Stinkhorns belong to the family Phallaceae, and what these 'shrooms lack (from our human perspective) in the olfactory department they make up for with their vivid colors and bizarre – but not necessarily phallic – shapes. Check them out at The Stinkhorn Hall of Fame at MushroomExpert.Com.