Top down view of leaves from the Digitalis purpurea (Purple Foxglove) plant, which are used to make the heart drug Digitalis. Growing in Spring, UK Stock Photo - Alamy
The Basics of Growing Foxglove Plants - Flower Magazine
Foxglove: How to Plant and Grow Foxglove Flowers | The Old Farmer's Almanac
Foxglove | Description, Poison, Uses, & Digitalis | Britannica