Thalictrum petaloideum

Thalictrum petaloideum is a perennial meadow-rue of the Ranunculaceae, native to northern China, Mongolia and adjacent Siberia, growing in grassland, meadows and on dry hill slopes. It forms clumps from a fibrous, yellowish rootstock and produces finely divided, blue-green leaves with small, rounded leaflets. The airy inflorescence bears many small flowers that lack true petals; instead, the showy part is a dense pompon of numerous white, petal-like stamens with broadened filaments (the epithet petaloideum, 'petal-like', refers to these). The fruit is a cluster of small ribbed achenes. Like other meadow-rues, the roots and rhizomes contain berberine and related isoquinoline alkaloids, giving the underground parts a bitter taste and yellowish colour. It flowers in early summer and is recognised by its delicate foliage and brush-like white flower heads.