Northern meadow-rue, pigamon des fronterières

Thalictrum turneri B. Boivin; T. venulosum Trelease var. confine (Fernald) B. Boivin

Stems erect, to 100 cm, from rhizomes. Leaves: cauline leaves 3-4, those proximal to inflorescence petiolate, those subtending panicle branches sessile. Leaf blade: leaflets reniform-cordate, apically 3-5-lobed, 15-50 mm wide, lobe margins crenate, surfaces glabrous to glandular. Inflorescences terminal, panicles, narrow with ascending branches, many flowered. Flowers: sepals yellowish to purple, oblong, 1.5-5 mm; filaments colored, not white; anthers 3-4.5 mm, mucronate; stigma purple. Achenes 4-13, erect, incurved, not reflexed, sessile; body fusiform to ovoid, not laterally compressed, adaxial surface 4-6 mm, glandular, veins prominent, not anastomosing-reticulate; beak (2-)2.5-4(-5) mm.

Flowering early-mid summer (Jun-Jul). Alluvial or shingly calcareous shores and talus; 0-200 m; N.B., Ont., P.E.I., Que.; N.Y., Vt.

The relationship between Thalictrum confine and T . venulosum is unclear and requires additional field study.