Lots of drawn-out writing, especially about anthropomorphization and linguistic issues. Not so much science. Do we have the wrong metaphors for fungi and plants? I couldn't care less. It is easy to write about, but not very scientifically productive.
Furthermore, even when it comes to science, every point is drawn out excessively, and the author gives a completely non-critical summary of lots of well-known phenomena. For example, fungal networks for computation. This is something that should be looked at carefully and critically, not just accepted with a "gee whiz" like a Wired magazine article. The chapter on psychedelics is a retread of Michael Pollan.
I really would have liked to have seen the author's own work be much more emphasized. Sheldrake is a biologist, or at least he has a Ph.D., but much of this book is just shallow interviews with other scientists, like you'd get from any journalist.
On the plus side, there was some good science. The most interesting parts to me, were the stories about fungal parasites, which are much more common than I had heard of. Also I was quite interested to hear about the plants that parasites on mycelial networks, ultimately getting their nutrition from other plants. I liked the author's perspective that mycelial networks are not just links between trees, but facilitate links between trees, possibly to help themselves. Allowing nutrients to flow from some trees to other trees and possibly back, helps the fungi keep a stable host ecosystem.
The illustrations, originally drawn with ink from Shaggy ink cap mushrooms, were also great.
> besides penicillin: cyclosporine (an immunosuppressant drug that makes organ transplants possible), cholesterol-lowering statins, a host of powerful antiviral and anticancer compounds (including the multibillion-dollar drug Taxol, originally extracted from the fungi that live within yew trees), not to mention alcohol (fermented by a yeast) and psilocybin (the active component in psychedelic mushrooms
> Some fungi have tens of thousands of mating types, approximately equivalent to our sexes (the record holder is the split gill fungus, Schizophyllum commune, which has more than twenty-three thousand mating types, each of which is sexually compatible with nearly every one of the others). The mycelium of many fungi can fuse with other mycelial networks if they are genetically similar enough, even if they aren't sexually compatible
> One partner plays a paternal role, providing genetic material only. The other plays a maternal role, providing genetic material and growing the flesh that matures into truffles and spores. Truffles differ from humans in that either + or - mating types can be maternal or paternal
> Fungi produce plant growth hormones that manipulate roots, causing them to proliferate into masses of feathery branches—with a greater surface area, the chances of an encounter between root tips and fungal hyphae become more likely.
> nematode-eating fungi only produce worm-hunting organs and issue a chemical summons when they sense nematodes are close by. If there is plenty of material to rot, they don't bother, even if worms abound
> The methods fungi use to hunt nematodes are grisly and diverse. It is a habit that has evolved multiple times—many fungal lineages have reached a similar conclusion but in different ways. Some fungi grow adhesive nets, or branches to which nematodes stick. Some use mechanical means, producing hyphal nooses that inflate in a tenth of a second when touched, ensnaring their prey. Some—including the commonly cultivated oyster mushroom (Pleurotus ostreatus)—produce hyphal stalks capped with a single toxic droplet that paralyzes nematodes, giving the hypha enough time to grow through their mouth and digest the worm from the inside. Others produce spores that can swim through the soil, chemically drawn toward nematodes, to which they bind. Once attached, the spores sprout and the fungus harpoons the worm with specialized hyphae known as "gun cells."
> Olsson and Adamatzky have shown that mycelium can be electrically sensitive, but they haven't shown that electrical impulses can link a stimulus to a response.
> they describe fossilized mycelium preserved in the fractures of ancient lava flows. The fossils show branching filaments that "touch and entangle each other." The "tangled network" they form, the dimensions of the hyphae, the dimensions of spore-like structures, and the pattern of its growth all closely resemble modern-day fungal mycelium. It is an extraordinary discovery because the fossils date from 2.4 billion years ago, more than a billion years before fungi were thought to have branched off the tree of life.
> Lichens encrust as much as eight percent of the planet's surface, an area larger than that covered by tropical rainforests. They clad rocks, trees, roofs, fences, cliffs, and the surface of deserts … Most rocky shorelines are rimmed with lichen. Lichens start where the seaweeds stop, and some extend down into the water.
> The names used to describe lichens sound like afflictions, words that get stuck in your teeth: crustose (crusty), foliose (leafy), squamulose (scaly), leprose (dusty), fruticose (branched). Fruticose lichens drape and tuft; crustose and squamulose lichens creep and seep; foliose lichens layer and flake
> In some situations, lichens reproduce without breaking up their relationship—fragments of a lichen containing all the symbiotic partners can travel as one to a new location and grow into a new lichen. In other situations, lichen fungi produce spores that travel alone. Upon arrival in a new place, the fungus must meet a compatible photobiont
> Lichens have evolved independently between nine and twelve times since. Today, one in five of all known fungal species form lichens, or "lichenize." Some fungi (such as Penicillium molds) used to lichenize but don't anymore; they have de-lichenized. Some fungi have switched to different types of photosynthetic partner
> The 'basic set' of partners is different for every lichen group. Some have more bacteria, some fewer; some have one yeast species, some have two, or none. Interestingly, we have yet to find any lichen that matches the traditional definition of one fungus and one alga."
> Abram Hoffer, a Canadian psychiatrist and researcher into the effects of LSD in the 1950s, remarked that "from the first, we considered not the chemical, but the experience as a key factor in therapy." … psychedelics like psilocybin "dope-slap people out of their story. It's literally a reboot of the system
> Layers of dead and un-rotted forest built up, storing so much carbon that atmospheric carbon dioxide levels crashed, and the planet entered a period of global cooling. Plants had caused the climate crisis, and plants were hit the hardest by it: Huge areas of tropical forest were wiped out in an extinction event known as the Carboniferous rainforest collapse.
> African Macrotermes termites are some of the more striking examples. Macrotermes, like most termites, spend much of their lives foraging for wood, although they aren't able to eat it. Instead, the termites cultivate a white rot fungus—Termitomyces—that digests it for them. The termites chew wood into a slurry that they regurgitate in fungal gardens, known as the "fungus comb," by contrast with bees' honeycomb. The fungus uses radical chemistry to decompose the wood.
> Mycoheterotrophs—"hackers" of the wood wide web—have lost the ability to photosynthesize and draw their nutrients from mycorrhizal fungal networks that lace their way through soil.