I believe Planet will talk to us if we are willing to listen. These fungal stalks behave as multistate relays: taken together, the neural net connectivity must be staggering. Can a planet be said to have achieved sentience?

- Lady Deirdre Skye, Planet Dreams, Alpha Centauri

Say you have a filament that's 1 µm in diameter, and 1 meter long. You want to fill up a 1m^3 (1m W x 1m H x 1m L) space with these, how many of these can you place in such a space? Over a trillion! And thus, the combined km length of these will also be over a billion km. At such small scales things can become very long when summed up.

100×10^12 km is about 10.6 light years. There are about 16 other stars closer to the sun than that. It's a bit like a human body containing blood vessels with total length greater than twice the Earth's circumference.

Interesting how deeply east coast Australia is colored. I live in Sydney, a city of 5.6 million humans, and yet my yard apparently has at least the following fungi I can identify to species level: Aseroe rubra (alien thing with tendrils), Astraeus hygrometricus, Cladia aggregata, Coprinellus disseminatus, Coprinellus micaceus, Cruentomycena viscidocruenta, Flavoparmelia caperata, Heterodea muelleri, Hypholoma fasciculare, Leratiomyces ceres, Mycena tenerrima, Myriostoma australianum, Omphalotus nidiformis (glows in the dark), Panellus luxfilamentus, Satyrus rubicundus (looks like a red penis), Scleroderma cepa, Scleroderma citrinum, Trametes coccinea, Trametes versicolor, Usnea hirta.

The map looks off. No way the American Southwest has 3 meters per cm cubed of fungal density in such an arid region. Plenty of desert.