Silver Wormwood

Artemisia ludoviciana is a rhizomatous perennial growing to heights of 0.3–1.0 m (0.98–3.28 ft). The stems bear linear leaves up to 11 cm long. The stems and foliage are covered in woolly gray or white hairs. The top of the stem is occupied by a narrow inflorescence of many nodding (hanging) flower heads. Each small head is a cup of hairy phyllaries surrounding a center of yellowish disc florets and is about 0.5 cm wide. The fruit is a minute achene. Flowers bloom July to October.

The plant is native to North America where it is widespread across most of the United States, Canada, and Mexico. Some botanists suggest that eastern United States populations have been introduced from the western and central part of the continent. Its habitats include dry slopes, canyons, open pine woods, and dry prairies.

A. ludoviciana is cultivated as an ornamental plant. Being rhizomatous, it can spread aggressively in some climates and gardens. It grows in dry to medium moisture and well-drained soil. It requires full sun. Popular cultivars include 'Valerie Finnis' and 'Silver Queen'. Both are hardy to USDA zone 4. 'Valerie Finnis' has held the Royal Horticultural Society's Award of Garden Merit since 1993.