Foxglove plant (Digitalis purpurea): how to identify it

What the ASPCA and Poison Control say

The ASPCA's foxglove entry lists Digitalis purpurea as toxic to dogs, cats and horses. The toxic principle it names is cardiac glycosides, and the clinical signs it lists are cardiac arrhythmias, vomiting, diarrhea, weakness, cardiac failure and death.

For people, Poison Control (the National Capital Poison Center) says all parts of the plant are poisonous, possibly even deadly, if swallowed, and that its flowers and fruit attract children. It describes a case in which a man picked young foxglove leaves believing they were borage, and he and his wife both needed hospital treatment for a dangerously slow heart rate.

What to do:

• A dog or cat chewed any part: call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435 at once (the ASPCA says a consultation fee may apply).
• A person swallowed any part: Poison Control says do not induce vomiting; if you are certain the plant was swallowed, go to the emergency room immediately, and if you are unsure, call 1-800-222-1222. In the UK, call NHS 111, or 999 in an emergency.

This page gives identification only: no handling, eating, medicinal or treatment advice, and no drug information. Plant Identifier's Toxicology tool gives AI-written notes for people, dogs and cats once a plant is named, but it does not replace those calls. The poisonous plants for dogs guide lists other common garden plants on the ASPCA's list, including oleander.

The first-year rosette and its look-alikes

Foxglove is a biennial. NC State says it forms "only a rosette of leaves the first year," and flowers the second. That rosette is the stage people misidentify.

Foxglove rosette. NC State describes a tight rosette of coarse leaves up to a foot long, with prominent veins, gray-white hairs on top and woolly or hairy undersides, kept low and close to the ground. The Woodland Trust says the leaves are oval and hairy "with a toothed margin."

Common mullein (Verbascum thapsus). NC State's mullein page describes a first-year rosette of large, silvery-green, velvety leaves, 4 to 12 inches long, pointed at both ends and tapering into a winged stalk, densely covered in woolly hairs, compared to lamb's ear. The Woodland Trust says mullein leaves are untoothed and hairier than foxglove's. In year two, mullein produces a dense spike of flat, five-lobed yellow flowers, never spotted bells.

Comfrey, borage and other leaves people eat or use as remedies. The Woodland Trust names comfrey as a plant that could be mistaken for foxglove out of flower, and Poison Control's case report above began with foxglove leaves picked as borage. This page deliberately gives no traits for telling foxglove from plants that are eaten, brewed or used as remedies: Poison Control says every part of foxglove is poisonous, possibly even deadly, if swallowed, and neither this page nor any app, Plant Identifier included, is a basis for picking leaves for any of those uses. If someone has swallowed leaves they picked, follow the Poison Control steps above.

Where it grows and naming notes

NC State gives the native range as western Europe and Morocco and grows it in USDA zones 4 to 9. Poison Control says foxglove grows throughout the United States, both in the wild and in gardens. In Britain the Woodland Trust describes it as a familiar wildflower of woodland edges, heathland, roadside verges, gardens and hedgerows, doing best on acidic soil.

Digitalis is the genus name; World Flora Online accepts Digitalis purpurea L. and places it in the plantain family, Plantaginaceae, as NC State does. The ASPCA still lists it under the older family name Scrophulariaceae. If you grow foxglove, NC State notes that deer avoid it; plant it away from vegetable and herb beds so its rosettes are never mixed up with leaves grown for the kitchen, and keep dogs from chewing it.