Coriaria sarmentosa aka Coriaria Ruscifolia

Coriaria sarmentosa, known as Tuhu, is native to New Zealand. It belongs to the Coriariaceae family. Kew lists its form as a perennial or subshrub. Plants for a Future describes it as a deciduous shrub. It grows to about 3.3 feet [1 metre] tall. Its wild range includes North, South and Stewart Islands. It grows in open ground, often on loose debris slopes. Its habitats stretch from the coast into upper mountain areas.

Plants for a Future gives July to August as its flowering season. Each flower has both male and female organs. The fleshy part called the fruit consists of petals. This distinction matters when reading accounts of its food use. The leaves yield black ink and can supply dye. The bark also has uses and contains much tannin. These uses do not make the plant safe to handle as food.

Choose a sunny spot with shelter for garden growth. Plants for a Future favours good loam for this species. It also lists sand and clay as suitable soils. The soil should stay moist but allow excess water to drain. The plant accepts mildly acid, neutral and mildly alkaline ground. The source gives mixed advice about shade. Its growing notes allow light shade, though its summary rejects shade. Sun is therefore the clearest choice from this evidence.

Cold limits where this shrub can grow outdoors in Britain. Plants for a Future reports tolerance to about −5°C. It records outdoor success from Sussex westwards. A sunny woodland edge is one suggested garden setting. The species can fix nitrogen, which adds to its garden value. Sow seed under glass in February or March. Germination can take one to three months at 15°C. Keep young plants under glass through their first winter. Plant them out after the last expected spring frost. Half-ripe cuttings offer another way to raise plants.

Poison risk is a major limit on its use. Plants for a Future describes all parts except the fleshy petals as highly poisonous. The seeds are among the toxic parts. It records past use of the fruit fresh and in drinks. Yet it also cites warnings against eating the fruit at all. These reports should not serve as a guide to safe eating. No medicinal uses are known in the supplied account. Its dye uses offer a clearer purpose than food use.