Thalictrum species are herbaceous perennials with nectarless flowers which don't have any petals. The sepals are small and inconspicuous in the majority of species while some hermaphroditic species have larger and/or colored sepals. Flowers have numerous stamens hanging down, which are sometimes the most conspicuous part of the flower. The 1- many pistils are simple and grow from 1 ovary each, and the fruits are dry achenes. Hermaphroditic (male and female functions within each flower), dioecious (separate sexes on different individuals) and andromonoecious (male and hermaphroditic flowers on the same individual) breeding systems are found in Thalictrum. The flowers grow in loose, open clusters. The leaves are both basal and alternate on the stem. They are compound, divided in threes, usually repeatedly 2 or 3 times. Leaflets are slender-stalked and often round with lobes. There are about 190 species of Thalictrum worldwide. Meadow rues are found in moist, open places throughout northern temperate regions. In the United States they are especially abundant in the Northeast. A few species are cultivated for ornament.
Guide to Identify Presented Species of Genus Thalictrum
T. occidentale Western Meadowrue Stems leafy, 40-100 cm tall. Moist, open to shaded sites, mountains.
Flowers male or female. Achenes 5-8 mm long, veined, slightly flattened.
Leaves alternate, thin, 3-4 times divided in 3s. Leaflets about 15-30 mm long.