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Harmless🍽️ Edible

🟢 Codium (dead man's fingers)

Codium fragile · Codiacées

🐚 Coastline🍁 North America
🧠 To remember it"Codium always splits in two" — each spongy branch forks into exactly two new branches, never three, a pattern recognizable at first glance.
Codium (dead man's fingers) — Codium fragile

🔍 Identify it without mistakes

Perennial green alga forming clumps of cylindrical dichotomous branches (always dividing in two), spongy and fuzzy to the touch, often compared to black fingers or dark green cauliflower. Native to the Pacific, widely naturalized and sometimes invasive in Europe and North America.

  1. dark green, cylindrical, spongy branches, always dividing in two (regular dichotomy)
  2. fuzzy and elastic texture to the touch, like thick velvet
  3. attached by a basal disc to rocks or shells, in the lower intertidal and subtidal zones
Size10 to 40 cm
Floweringno flowering (alga)
Habitattemperate rocky coasts worldwide, widely introduced outside its native Pacific range to Atlantic Europe, the English Channel, and Atlantic coasts of North America where it is classified as an introduced species

⚠️ Not to be confused with

No known dangerous look-alikesaucun

To tell them apart: the unique spongy and fuzzy texture, dark green color, and systematic branching into two equal branches are not found in any toxic coastal seaweed

🍽️ Eating it

Partsentire branches
Seasonété-automne
Tastemild, slightly salty, distinctive spongy texture to chew

Preparation : rarely used fresh as is in Europe (the spongy texture is not widely appreciated raw), rather dried and added in small pieces to soups and broths, or used in Asian cuisine where it goes into certain seaweed salads after a brief blanching

💊 Healing with it

studied for its potential antibacterial and antibiotic properties derived from its bioactive compounds

Level of evidence : limited studies — DORIS (FFESSM) — Codium fragile

⚠️ as with any seaweed, avoid harvesting in port or polluted areas

Sources (2)

No entry replaces a certain identification in the field, or medical advice. When in doubt: don't eat it. If ingestion is suspected: poison control or 112/911.