Onopordum nervosum

Onopordum nervosum, also known as donkey thistle, is a monumental biennial botanical species. In late summer it produces large globular and purplish inflorescences over 2 metres (7 feet) above the ground, resembling giant centaurea flowers. Highly ornamental, the plant is also full of ambivalence, both gentle and formidable, armed with sharp thorns from the grey and furry leaves to the thick white cottony stems. A plant that commands admiration, like an ancient knight, modest enough to prefer rather chalky and dry soils, yet lavish enough to demand full sunlight.

Onopordon nervosum, widely spread in central Europe in uncultivated land, is sometimes called false acanthus or Scottish thistle. It belongs to the Asteraceae family and has a biennial growth cycle. This thistle dies in its second year of cultivation but generously self-seeds, especially in cracks in pavements, rocks, and bricks. In its first year, it forms a large persistent rosette of long whitish-grey leaves, covered in hairs, wide and spiny, deeply incised. In its second year, a huge branched stem covered in white tomentum, bearing numerous ridges, rises from the heart of the basal rosette, also carrying large spiny whitish-grey leaves. Each stem ends in a head-like inflorescence, composed of a green receptacle topped with purplish flowers arranged in a brush-like manner. The root is a thick, powerful taproot, making transplantation a little delicate for a well-established specimen.

In fact, the donkey thistle self-seeds wherever it finds the smallest crack within reach of its seeds. It is simply stunning when paired with blue delphiniums and pink roses in moist soil, but also blends well with giant grasses (Panicum virgatum, Miscanthus sinensis), Cephalaria gigantea, hollyhocks, or tall mulleins in dry gardens. A plant to be admired in a distant bed, away from pathways and children, for its presence and for the fascination exerted by its sharp, almost metallic texture, coupled with a somewhat futuristic appearance.