- Family: Violet Family – Violaceae
- Growing form: Perennial herb. Rootstock erect, large-scaled, brown.
- Height: 15–30 cm (6–12 in.). In spring stem almost a leafless scape, leafy growing stem later, hairy on one side.
- Flower: Corolla zygomorphic, light purple, approx. 2 cm (0.8 in.) wide; petals 5, with faintly notched tip, lowest with spur. Sepals 5. Stamens 5. A single carpel. Flowers solitary, nodding, weakly fragrant.
- Leaves: With basal rosette and alternate on stem, stalked, stipulate. Blade widely cordate–kidney-shaped, with rounded teeth (crenate), underside sparsely hairy, light green. Stipules narrowly ovate, with entire margins, soon withering.
- Fruit: Elongated, glabrous, 3-lobed, approx. 10 mm (0.4 in.) long capsule. Scape erect in fruiting stage, only curved at tip.
- Habitat: Broad-leaved forests, foot of crags, coppices.
- Flowering time: May.
Wonder violet can be most likely found in rich broad-leaved forests along with other forest jewels such as small-leaved lime, hazel, mezereon, baneberry and Suffolk lungwort. The species is most common in Finland between the south coast and southern Häme, and it is quite abundant in broad-leaved forests in northern Savo and northern Karelia. The northernmost stands are in Kainuu and on the lower River Kemijoki.
Carl von Linné himself gave wonder violet it’s scientific name mirabilis, meaning admirable and special. The species is certainly large and impressive, but the name comes from the way the plant annually changes its form, which is unique among violets that grow in Finland and rare in the plant world in general. The root buds sprout a large leaf rosette in spring and quite a large and long-stalked, pleasant-smelling flower. Over the summer the rootstock develops a tall stalk which has short-stalked leaves and several flowers without corollas that fail to open properly. In the autumn the aerial parts wither and the cycle begins again.
The tall spring flowers look impressive, but they often fail to produce much seed. The reasons for such poor seed production are not completely clear, but the scarcity of pollinators in the spring, lack of visibility in the forest and the way that the flowers are hidden by the large leaves are significant factors. The seed production of self-pollinating summer flowers is always good, so wonder violet’s future is secure. Descendants do not however go through the annual transformation which would be beneficial should the prevailing conditions, which are currently good for the plant, change. Wonder violet is a vulnerable species in other ways too because its rhythms are slow and a germinating seed will take at least 6 years to flower, often a decade.