MyceliaCerebrum fungorum
Plate i·of seven·Spring MMXXVI

a note-taking instrument, est. 2026

Thoughts, cultivated.
A second brain
that grows.

Most note apps are filing cabinets. Myceliais a forest floor — a living network of root, rhizome, and spore where your ideas nourish each other quietly, in the dark, between sessions.

(it learns from what you leave behind.)

Plant your first note↗Browse the field guide
Fig. iAmanita cognitionisscale 1 : 1
— soil line —a. pileus — the visible noteb. stipe — the draft beneathc. hyphae — associationsd. rhizomorph — a thread of thoughte. spore — an idea loosed into the world
Observed 04/XVI/26·sketch from life— AR
ii.

Specimens in the Vivarium

Each of these is a small organism that lives alongside your notes and works for you when you are not looking.

i
Hyphae linkensis“the linker”

Silently weaves a web between every phrase you write. Two notes touch when their sentences resonate, not when you remember to tag them.

habitatevery note, always
ii
Rhizoma diurnum“the daybook”

A single continuous page for the day — your thoughts, arrivals, overheard remarks. Fades softly into tomorrow's at midnight.

habitatthe front of the brain
iii
Fructus memoriae“the fruiting body”

Surfaces the three ideas most worth revisiting this week. Not by recency — by resonance. What you’ve been circling around.

habitatsunday mornings
iv
Sporae dispersae“the publisher”

Send a single leaf, or a small grove, to a reader of your choice. Hand-set, unstyled, an honest page.

habitatthe garden gate
v
Radix profunda“the archive”

A deep, plain-text cellar. Your notes live on your disk as markdown; the network is a layer on top, not a cage around them.

habitatyour own machine
vi
Sentinel herbarius“the keeper”

Gently points out the note you wrote in May that predicted the thing you’re arguing with yourself about today.

habitatthe margins
iii.

Field notes

04/14 — tuesday, overcast

the trouble with folders is that they assume you know what a thing is before you meet it. a thought, unfiled, can sit beside other unfiled thoughts and show you what it is. this is, i think, how memory actually works.

— caretaker's log

the idea-in-itself
fig. ii— a sporing body, isolated
the trail of attention
fig. iii— linked traversal, tuesday

“The mycelial network does not retrieve information; it remembers together. Our app is built in the same spirit.”

— field notebook, entry 042

Join the vivarium.

One letter per new moon. Seasonal updates on what has been growing. No marketing. Ever.

ps. the second brain is a habit, not a feature. we are in no rush.