Phacelia tanacetifolia is a species of phacelia known by the common names lacy phacelia, blue tansy or purple tansy. Phacelia tanacetifolia is an annual herb which grows erect to a maximum height near 100 centimeters with none to a few branches. The wild form is glandular and coated in short stiff hairs. It used outside its native range in agriculture as a cover crop, a bee plant, an attractant for other beneficial insects, as a green manure and an ornamental plant. It is planted in vineyards and alongside crop fields, where it is valued for its long, coiling inflorescences of nectar-rich flowers which open in sequence, giving a long flowering period. It is a good insectary plant, attracting pollinators such as honey bees.