Side by side
What tells them apart
Before flowering they are very alike, and that is when the mistake happens. Comfrey's leaf runs down the stem as two wings, and the plant is rough with stiff bristles; foxglove's grows in a rosette, is velvet-soft and does not run down the stem. Without a flower, gather neither.
Confusion that kills
How to tell it
The whole plant is covered in stiff bristles that prickle lightly. Large lance-shaped leaves running down the stem as wings, which foxglove does not do. Bell flowers, purple, pink or white, on a stem coiled like a scorpion's tail.
How to tell it
A tall spike with tubular flowers hanging on one side only, purplish pink and spotted dark inside. In its first year it is only a rosette of large soft leaves at ground level, and that is when it is dangerous, because it looks like nothing.