Eastern Pasque Flower
- Name also: Eastern Pasque-flower, Prairie Crocus
- Latin synonym: Anemone patens
- Family: Buttercup Family – Ranunculaceae
- Growing form: Perennial herb. Rootstock short, erect.
- Height: 10–30 cm (4–12 in.), in fruiting stage up to 50 cm (20 in.). Stem unbranched, soft-haired, leafless apart from whorl underneath flower, extends after flowering.
- Flower: Perianth regular (actinomorphic)–widely campanulate, blue–bluish violet, approx. 7.5 cm (3 in.) wide. Tepals 6 borne in 2 whorls, all almost same size, outer surface white-haired. Stamens many, anthers yellow. Gynoecium separate, with many pistils. Flower solitary, terminating scape.
- Leaves: Basal leaves long-stalked, stalks hairy, developing after flowering. Blade with 3 leaflets; leaflets stalkless, 3-lobed, lobes quite wide, slightly hairy. Upper leaves borne in a whorl below flower, fused at base, finely lobed, green, white-haired.
- Fruit: Approx. 3 mm (0.12 in.) long achene, tip with 2–5 cm (1–2 in.) long, densely haired bristle. Achenes in clusters.
- Habitat: Dryish ridged slopes, dry moors.
- Flowering time: May.
- Endangerment: Critically endangered, protected in all of Finland. Also the hybrid between eastern pasque flower and spring pasque flower (Pulsatilla patens × vernalis) is protected.
Eastern pasque flower is a steppe plant which spread to Finland as soon as the continental ice retreated. The change in the climate that followed the Ice Age was favourable for the species and it was probably common and abundant. Eastern pasque flower still grows across a wide swathe of central and eastern Europe, as well as northern and central Asia. Our Finnish climate favours forest and bogs has led to a decline in steppe plants, and eastern pasque flower still grows in only a very small area on dry and sunny ridged slopes around Hämeenlinna. People have also played a part in the decline of the species: at the beginning of the 20th century pasque flowers were freely sold in Hämeenlinna, and people transplanted them from the wild to their own gardens until the Nature Conservation Act was enforced in 1952. Eastern pasque flower still grows in around 150 places in Finland, and attempts have been made to carefully protect these. The species is very long-lived and in favourable conditions it blooms again and again from one year to the next.
The blame for eastern pasque flower’s sad demise can be laid at the door of its flowers, which are among the largest to be found in the wild in Finland, being around the size of a small coffee cup. One plant had as much as 80 flowers. Bees, butterflies, flies and certain beetles buzz around gathering nectar. After flowering a disarmingly furry infructescence develops, and the leaves also grow at this time. Old plants’ strong, branched roots can support more than 100 leaves.
Apart from eastern pasque flower, light-flowered spring pasque flower (A. vernalis) also grows wild in Finland, mainly on ridges in the south-east of the country and on Salpausselkä. The species meet each other in the Lammi–Tuulos area, where they commonly cross-breed, producing a hybrid (Pulsatilla patens × vernalis) whose flower is open like spring pasque flower but is a light purple colour.