As soon as you begin to look at the natural world there are never-ending chains of relationships between living organisms. The classic poem from Augustus de Morgan says:
“Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on,
While these again have greater still, and greater still, and so on.”
That’s just a linear relationship, while in the natural world there are multiple dimensions of relationships between thousands of species and across time.
Today I’m looking at a mushroom growing on a mushroom. It’s one of my favourites, the rare Pseudoboletus parasiticus the Parasitic Bolete growing on Scleroderma citrinum, the Earthball.
Just because Pseudoboletus parasiticus has ‘parasite’ in its name doesn’t mean that it is actually parasitic. It certainly grows on Earthballs, but how much does it affect the success or reproductive capacity of the Earthball? The impact of one species on another can be a complex calculation and biologists are often muddled in their thinking of what a ‘benefit’ or ‘harm’ is from one species or individual to another.
As a student I was taught there were three different relationships between organisms: mutualism; commensalism and parasitism. Mutuals are said to get mutual benefit, a commensal relationship is where just one benefits and the other is not harmed, and parasitism is where the relationship is beneficial to one and harmful to the other. I’ve had relationships like that. All three are flawed ideas which simplify real relationships to the point of absurdity with often very limited scientific evidence to support them.
Here’s another one with the so-called Parasitic Bolete just emerging:
It’s a lovely find, whatever the relationship between them.