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All Grades

School garden-science lessons included on this page are appropriate for all grade levels.

May 10th – The Birdhouse Gourd Project

May 3rd – Garden Update

March 29th – California Ecosystems: Northcoast Forests

March 22nd – California Ecosystems: Grasslands

March 15th – Bees in Early Spring

March 8th – Garden Update! March

March 1st – Strawbale Garden: One month later

February 22nd – School Garden Update

February 8th – Intro to Geology

February 1st – Strawbale Experiment

January 25th – Death Cap

Text and photos by Trent Pearce, Naturalist, Tilden Nature Area


After the first fall rains, the East Bay hills come alive with mushrooms. Sprouting in an array of dazzling colors, these fungal fruitbodies can be beautiful – but some of them are deadly poisonous.

The Bay Area is home to two of the world’s most toxic mushrooms – Amanita phalloides (the Death Cap) and Amanita ocreata (the Western Destroying Angel). Both are robust, handsome mushrooms that grow near oak trees, and both contain lethal toxins.

Amanita phalloides (the Death Cap) is a medium to large mushroom that typically has a greenish-gray cap, white gills, a white ring around the stem, and a large white sac at the base of the stem. It fruits early in the fall, usually right after the first rains. Though the Death Cap is mainly associated with oak trees, it has been found growing with other hardwoods. It was accidentally introduced to North America on the roots of European cork oaks, and is now slowly colonizing the West Coast.

Amanita ocreata (the Western Destroying Angel) is a medium to large mushroom that usually has a creamy white cap, white gills, a white ring around the stem that disappears with age, and a thin white sac at the base. It fruits from late winter into spring, and is associated exclusively with oaks. Unlike the Death Cap, it is a native California mushroom.

Both of these species contain amatoxins, a group of molecules that inhibit cellular metabolism in many animals. In mammals, the liver and kidneys are typically the first organs affected after ingestion. Symptoms don’t usually appear until up to 12 hours after consumption, beginning as severe gastrointestinal distress and progressing to liver and renal failure if treatment is not sought immediately.

While these two species are responsible for most cases of mushroom poisonings in California, deadly amatoxins can be found in Galerina and Lepiota species as well, both of which occur in the Bay Area.

Park visitors should remember that mushroom collecting is not allowed anywhere in the East Bay Regional Park District. If you are legally harvesting mushrooms elsewhere, learn these two species before any others and do not let them end up on your dinner table. Pet owners are encouraged to keep their animals under close watch during the winter months, and contact a veterinarian immediately if you suspect your pet has eaten a toxic mushroom.

Recommended reading: Mushrooms of the Redwood Coast, Siegal & Schwarz. 10-speed Press, 2016.

Amanita ocreata
Amanita phalloides
Amanita phalloides
Galerina marginata
Amanita ocreata
Amanita phalloides


January 11th – Turkey Tail and Artist Conk

December 14th – Chicken of the Woods

  • This mushroom is a polypore, meaning they disperse spores through small pores (holes) on the underside of their caps.
  • The different species of the chicken of the woods mushroom are both saprotrophic (feeding on dead trees), and parasitic (attacking and killing live trees by causing the wood to rot). Whatever their method of feeding, you’ll always find them growing on or at the base of a living or dead tree.
  • Chickens are easily recognized by their large clusters of overlapping brackets, and bright yellow-orangish colors. The colors fade as the mushroom grows older.
  • Many polypores are also medicinal mushrooms, although there hasn’t been much research done on this one.
  • Other names are chicken fungus, chicken mushroom, and sulphur shelf. The genus is Laetiporus.
  • There are about twelve species of chicken of the woods in the Laetiporus genus.

November 2nd – Stinkhorns

It “hatches.” It smells like death. Some have a questionable shape. What’s not to love about stinkhorn mushrooms?

Stinkhorn mushrooms like to grow on rotting organic matter, so you typically find them in your mulch beds. Like all mushrooms, what we see is only a small part of the actual fungus. Under the ground, there are thousands of threads called mycelium. Every so often, the fungus sends up a fruiting body we can see to release spores so that it can spread. In the case of the stinkhorn mushroom, it sends up a young fruiting body that almost looks like an egg. As it matures, the mushroom appears to “hatch” from the egg, rapidly growing!

Stinkhorn mushrooms emit a fetid scent (a stinking smell) meant to attract flies and beetles that aid in the spread of the stinkhorn spores. So keep your eyes and nose on the lookout for stinkhorn mushrooms in your neighborhood.

October 19 – Sisters are soooo helpful

Do you have siblings? Ms. Ashley does. Here is her sister pretending to be Ms. Ashley giving a gardening lesson.

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