- Written also: Greater Meadow Rue
- Family: Buttercup Family – Ranunculaceae
- Growing form: Perennial herb. Rootstock short.
- Height: 50–150 cm (20–60 in.). Stem branched, finely grooved.
- Flower: Regular (actinomorphic), light purple–white, 10–15 mm (0.4–0.6 in.) wide. Petals lacking. Sepals 4–5, obovate, purplish–greenish, falling early. Stamens many, filaments club-like, clearly longer than anthers and upper part thicker than anthers, usually purple (sometimes pink or white). Gynoecium separate, with many pistils. Inflorescence dense compound corymb, flowers erect.
- Leaves: Alternate, lowest stalked, upper stalkless, stipulate. Basal leaves 1–2, stem leaves 4–5. Blade triangular, 2–3 times ternate. Leaflets stipulate. Secondary leaflets roundish, wide-based, with round and large-toothed tip, glabrous, light green.
- Fruit: Obovate, with 4 ridges, 5–15 mm (0.2–0.6 in.) long, bristle-tipped, long-stalked achene.
- Habitat: Broad-leaved forests, rich mixed swamps. Also ornamental and an escape from cultivation in forest margins and banks.
- Flowering time: July.
- Endangerment: Vulnerable, protected in all of Finland.
Greater meadow-rue was not found in Finland until 1956 in Närsäkkälä in Kitee, really close to the eastern border. New finds in Otravaara and Silovaara in North Karelia in the 1970s raised the number of stands to three, and more stands might yet be found in eastern Finland. Potential habitats would be damp and semi-shaded rich mixed swamps. The species avoids both very open and very shaded places.
Human activity has confined the stands in Otravaara and Silovaara, and the stand that grew on Hiidensaari on the 1960s has apparently disappeared. On the other hand the species’ known habitats are also cared for in such a way that the light at the flowering vascular plant level encourages its growth and the development of habitats that favour it, although there is not so much that it would benefit the competition too much.
Greater meadow-rue’s modest tepals protect the developing flower and they drop off as soon as the bud opens. The colourful and fragrant stamens attract would-be pollinators, which are rewarded with pollen. The stamens’ filaments are the most visible part of the plant and the way that they thicken towards the tip is an easy way to differentiate the species from its relatives. Greater meadow-rue is also cultivated in parks for its long and abundant flowering time. The species thrives in quite dry places too and has escaped into the wild in a few places. Escapes are usually native to central Europe – attempts to transplant wild Finnish plants into gardens do not usually fare well.