This tool aids identification but does not replace an expert. Never eat a wild plant or fungus on the strength of a single feature. When in doubt, throw it out.
Common Comfrey can be confused with 1 dangerous plant/fungus. Check every distinguishing feature before you trust an identification.
All parts contain heart poisons; the non-flowering leaf rosette is easily mistaken for comfrey, mullein or borage, and ingestion causes nausea, disturbed colour vision and dangerous, potentially fatal heart-rhythm disturbances.
Confusable part: Young non-flowering basal-rosette leaves gathered in spring for tea or infusion, before either plant flowers.
Comfrey and foxglove both form a ground rosette of large, soft-hairy, grey-green oval leaves, and comfrey leaf is exactly the part harvested for herbal tea. Foxglove leaves contain cardiac glycosides and are potentially fatal; documented poisonings include a woman who developed heart block after an infusion of 'boiled comfrey leaves' that was actually foxglove, and an outbreak of nine people poisoned by 'comfrey' tea that was foxglove. The plants are hardest to tell apart before flowering.
How to tell them apart
- Leaf margin (most decisive): comfrey leaves are entire — a smooth, unbroken edge. Foxglove leaves are finely toothed or scalloped along the whole margin.
- Comfrey leaf bases run down the stem as raised wings (decurrent), so the stem looks winged; foxglove leaves narrow to a stalk and do not wing the stem.
- Comfrey hairs are stiff, coarse and bristly (rough to the touch); foxglove leaves are softly downy and velvety, with a grey-felted, net-veined underside. Do not rely on hairiness alone — both feel hairy.
Look closely at the leaf edge: a smooth, untoothed margin plus a leaf base that runs down the stem as a wing = comfrey. A continuous line of small teeth or scallops along the edge = foxglove — do not use it. If the margin is not clearly untoothed, do not forage.
Educational identification aid compiled from the Omnia Sana plant database and cited botanical and toxicological sources. Not medical advice and not a substitute for expert identification.