- Family: Violet Family – Violaceae
- Growing form: Perennial herb. Rootstock creeping, often with runners.
- Height: 8–16 cm (3–6.5 in.). Stem almost a leafless scape.
- Flower: Corolla zygomorphic, strongly blue–purple, 2–3 cm (0.8–1.2 in.) wide; petals 5, clearly notch-tipped, lowest with a thick, purple spur. Sepals 5. Stamens 5. A single carpel. Flowers solitary, nodding.
- Leaves: With basal rosette, stalked, stipulate. Blade ovately cordate, clearly tipped, with rounded teeth (crenate), glabrous, light bluish green, basal notch shallow, wide. Stipules fused with leaf stalks, almost with entire margins.
- Fruit: 3-lobed capsule.
- Habitat: Shoreside meadows, meadows, rich mixed swamps, periodically flooded swamps.
- Flowering time: May–June.
- Endangerment: Endangered, protected in all of Finland, including the Åland Islands.
Finland is the northern limit of bog violet’s growing area. It demands light, heat and damp habitats. Marsh violet has the most impressive flowers of all the Finnish violets, but its destiny has been harsh: there are not many rich, damp seashore meadows in Finland and there have never been more than 20 stands in the country, and now most of them have disappeared. Currently, bog violet probably only grows in small quantities in Hankoniemi, Karkku, Kökar and Mäntsälä.
The tough place that bog violet finds itself in is due to changes in the environment: the amount of land that lies between the shoreline and the forest margin and the habitat of species that have adapted to flooding has decreased markedly in recent years. The excessive growth that results from controlling the natural rhythm and volume of flooding is connected to the draining of wetlands, the construction of shore embankments and an increase in summer houses, all jostling for space. This has taxed rich shore meadows, which were rare to begin with. Plants that grow in floodlands temporarily benefited from the use of shores for grazing cattle. Although a plant-munching cow might not be the first thing that comes to mind when thinking of plant protectors, cattle maintained a suitable, open flood-influenced meadow for marsh violets. Shore grazing has ended in the last decades and former pasture meadows have begun to grow reeds and sedges below the water line and bushes above it.
The bell has tolled for bog violet elsewhere too: stands have been disappearing in the same way across Europe as they have in Finland. The species doesn’t grow outside Finland, and no longer very widely in its central European homeland either. Although Finnish habitats are only a small fragment of the species’ overall habitat, plants that grow in the country are also important from the point of view of the existence of the species as a whole.