Though this column is about planting, it’s technically not about a plant. It is about a very special type of organism: the mushroom. Fungi are their own kingdom consisting of over 12 million species. Although fungi seem similar to plants, DNA sequencing has revealed that fungi are actually more closely related to animals.
Plants are autotrophs, meaning they use photosynthesis to produce their own food from light and molecules in the air. Fungi, like animals, are heterotrophs. They obtain nutrients from other organisms and organic material. What differentiates animals from fungi is that while animals ingest and digest food, Fungi secrete digestive enzymes into their environment and then absorb the nutrients released – pretty crazy right?
Unlike plants, which reproduce by creating seeds, (which you hopefully read about in my last column!) fungi grow from either spores or tissue culture. Every mushroom releases thousands of microscopic spores, each spore containing its own unique genetic material. Growing spores is very similar to planting apple seeds because it is unpredictable: each spore will sprout a mushroom totally different from its parent. When a spore lands in the right environment, which is usually damp and rich with decaying plant matter, the spore grows a small thread called a hypha. As hyphae continue to grow and branch, they form a network similar to a root system called a mycelium. Signals like a change in moisture, temperature, or humidity prompt the mycelium to condense, forming primordia, or “pins”, which are the smallest stage of mushrooms. Primordia grow to form mature mushrooms which release spores, allowing for the cycle to begin again.
Mushrooms can be foraged in the wild, and there are many mycological clubs where mushroom lovers, or mycophiles, can exchange knowledge and build community around mushroom foraging. But, mushrooms can also be cultivated. Sasha Gomes, a senior in BIHS, has grown oyster mushrooms in her own backyard.
When a friend started growing mushrooms, Gomes took it upon herself to do the same. She explained the process, which begins with purchasing spawn and substrate. Spawn is the material that has been inoculated with a specific strain of mycelium, or “mushroom culture.” There are many types of spawn, but the most popular for home growers are grain spawn and sawdust spawn. “The substrate is what you put the spawn in. It’s where the mycelium can grow and the mushrooms feed off of it,” said Gomes. “I boiled the straw to make it really sterile, so there’s no competing bacteria and it won’t mold over,” Gomes explained. Then, she layered the spawn and substrate in a laundry basket, distributing the broken up sawdust into the straw.
“Over the next few weeks, I saw the mycelium, which looks like this fuzzy white stuff, spreading through the straw,” Gomes recalled. “Sometimes I would go out and there’d be like a new little mushroom that wasn’t there the day before. It was just a very cool and exciting thing to see.”