In early 2002 I decided to try to grow a packet of Cordyline australis (cabbage palm tree) seeds I had been given a few years previously, in the hope that they would still be viable. However, a couple of weeks after I sowed them I was alarmed to see that each seed had grown a clump of white fungus; however, all the tufts of sporangia seemed to be pointing in the same direction, in a very peculiar way - see the picture below:

After puzzling over it for a while, I realised that all the fungi were growing towards a nearby window, exhibiting phototropism. This seemed bizarre to me, as fungi are heterotrophs, extracting nutrients from whatever they are growing on, and so should not have any response to light!

However, I found a possible explanation in the textbook Biology by Campbell et al, on p587 in the third edition:

"...Some zygomycetes, however, are actually able to aim their spores. One is Pilobolus, a fungus that decomposes animal dung. Pilobolus bends its sporangium-bearing hyphae toward light, a direction where grass is likely to be growing. The whole sporangium is then shot off on an explosive squirt of cytoplasm out of the end of the hypha, sometimes carrying the sporangium as far as 2m. This adaptation disperses the spores away from the mass of dung and onto surrounding grass, which will be eaten by a herbivore such as a cow. The asexual life cycle is completed when the animal scatters the spores in feces."
(my underlining)

A quick search on the internet turned up other references to the fungus, such as Fun Facts about Fungus, as well as other species that do the same including Sphaerobolus stellatus. I hope the descriptions of the fungi's substrates do not accurately reflect the compost I was using, though!