Solidago caesia. An Eastern North American native has arching stems with lance-like, alternate leaves. Yellow flowers appear on the top of the branches, making a great display. Not to be confused with allergen producing plants. Great in woodland garden, borders, and butterfly gardens. Grows 2-3' tall by 1' wide. Blooms in late summer. Full sun to part shade. Plant in well-drained soil. Zones 4-8.