Coriaria myrtifolia aka French Sumac

Coriaria myrtifolia is a deciduous shrub in the Coriariaceae family. Its common names include redoul and myrtle-leaved tanner's tree. It also goes by the name myrtle-leaved sumach. Its native range spans the western Mediterranean to western Greece. Records include Spain, France, Italy, Greece, Algeria and Morocco. It is not native to Britain or Ireland. In the wild, it grows in dry woods, hedges and rocky places.

The shrub reaches about 6 feet [1.8 metres] in height. It loses its leaves during the year rather than staying evergreen. Its leaves and bark contain large amounts of tannin. Flowers appear from July to August, according to Plants For A Future. Each flower has both male and female organs. The plant can fix nitrogen, a useful trait in garden soils. Its value is not limited to its summer flowers.

Choose a sheltered spot with sun and good loamy soil. The shrub also grows in light shade, including a woodland edge. It accepts sandy soils and clay as well as loam. It tolerates mildly acid, neutral and mildly alkaline soil. In cultivation, it prefers moist ground despite its dry wild habitats. Plants For A Future lists USDA zones 7–10. It also reports cold tolerance down to about 23°F [−5°C]. In Britain, outdoor growth succeeds from London toward the southwest. Winter cold can kill the stems back to the ground. Plants often send up new shoots from their base. Those shoots do not flower in their first year.

The leaves provide material for black dye and ink. The bark also has uses linked to its tannin content. Crushed fruits have served as a poison for flies. These uses do not make the shrub safe to eat. Plants For A Future describes it as very poisonous. It lists no edible uses and no known medicinal uses. Keep its toxic nature in mind when choosing a planting site.

Seed and half-ripe cuttings offer two ways to raise new plants. Sow seed under glass in February or March. Germination takes one to three months at about 59°F [15°C]. Grow young seedlings under glass through their first winter. Move them outside after the last expected frosts. Take half-ripe cuttings with a heel in July or August.