Thalictrum dioicum

Native

Moderate moisture. Woods. Partial sun to shade.

April to May

Greenish to purple-brown

12″ to 28″

This is a 12″ to 28″ tall, erect, perennial forb that rises from fibrous roots and a stout caudex. Staminate flowers (male) and pistillate flowers (female) are borne on separate plants. This plant blooms in the early spring before deciduous trees leaf out.

Stems are erect, hairless, green, and often branched in the upper half.

All leaves are on leaf stalks. Stem leaves are alternate. They are 3 or 4 times ternate—divided into 3 main divisions (ternate), each division further divided into 3 segments (biternate), each segment further divided into 3 leaflets (triternate), or once more divided. The leaflets are ⅓″ to 1¾″ wide and wider than long. They are kidney-shaped, heart-shaped, round, or inversely egg-shaped with the attachment at the narrow end. The leaflets have 3 to 12 often round-toothed lobes. The upper surface is hairless and usually green, sometimes bluish due to a whitish, waxy coating (glaucous). The lower surface is hairless but may have short, rounded, nipple-like glandular bumps or projections.

The inflorescence is a small, up to 6″ tall, branched cluster at the end of the stems and branches and in the leaf axils.

Male flowers have 5 greenish to purple-brown petal-like sepals. There are no petals. They droop at the end of short stalks. The sepals often drop off early leaving about 12 stamens with yellow to greenish-yellow filaments and anthers. The flowers do not produce petals or nectar to attract insects. They are wind pollinated.

The fruit is an achene over ⅛″ long.

Tall meadow rue (Thalictrum dasycarpum) is a much taller plant, 3′ to 5′ at maturity. Middle and upper leaves are stalkless. The leaflets are as long as wide, or, more commonly, longer than wide. The larger leaflets are divided into 2 to 5 but usually 3 lobes. The lobes are untoothed or occasionally have a few additional teeth. The flowers bloom later, June to July.

Waxy leaf meadow rue (Thalictrum revolutum) is a much taller plant, 3′ to 7′ at maturity. The stems are glaucous. Middle and upper leaves are stalkless. The leaflets are as long as wide, or, more commonly, longer than wide. Leaf margins are rolled backward to the underside. The larger leaflets are divided into 2 to 5 but usually 3 lobes. The lower leaflet surface is covered with glandular hairs giving it a whitish, waxy appearance, and has a conspicuous network of raised veins.