The leaves of Lovage taste similar to celery and are often used in salads and soups. However, like all members of the Apiaceae family it contains coumarin, a chemical that causes skin redness, burning and blisters on the skin of people (and also livestock) who have eaten or handled the leaves and whose skin is subsequently exposed to sunlight.
The coumarin content is highest in the root of the plant, and we do not know the content of the leaves. Although the skin of reptiles is different to that of mammals, we do not know the consequences for tortoises if they eat plants containing coumarin, and because research also shows that parts of Lovage have diuretic properties, we do not advise feeding this plant to your tortoise, but no great harm will come if some is accidentally nibbled.
The flowers of Lovage appear to be yellow but on close inspection they are actually cream with large stamens that are yellow.