Silphium mohrii

Silphium mohrii, also known as Mohr's Rosinweed, is a tall perennial with generous lemon-yellow flower heads in summer. It has a natural and wild charm with a clump of large basal leaves from which sturdy upright stems emerge which stand up well to the wind and bear numerous daisy-like flowers. It vigorously enlivens and revitalizes the landscape in the summer. Silphium mohrii is hardy and easy to grow in the sun, in well-drained soil that doesn't dry out in the summer.

Silphium mohrii belongs to the Asteraceae family. The genus Silphium, also known as Rosinweed, Silphon or Colophane, comprises about twenty perennial herbaceous species native to the United States and Canada. Mohr's Rosinweed is a tall deciduous perennial with a robust crown from which large square, stiff and straight stems emerge in spring, holding up well in the wind. The matte green, lanceolate leaves can measure up to 40 cm (16in) long if the plant is grown in deep, rich and moist soil. Sheathing the base of the stems, they are opposite, triangular, hairy and without petioles and quickly form a thicket of multiple thick, hairy and vigorous stems, with sap that smells of turpentine. The slightly fragrant flowers resemble large lemon-yellow daisies 5 cm (2in) in diameter at the end of branching stems from July to September. The plant reaches 1.20 to 1.50 m (4 to 5ft) high with a spread of 50 cm (20in).

Silphium mohrii is the perfect plant to accompany large grasses like Miscanthus, Cortaderia or bushes in an open and sunny garden. It adds its architecture to robust perennial borders with Rudbeckias or Virginian Cataleptics. This plant is loved by pollinators and will thrive without needing much care in both urban and rural areas.