- Family: Diapensia Family – Diapensiaceae
- Growing form: Perennial dwarf shrub. Forms dense, semi-spherical cushions.
- Height: 2–6 cm (0.8–2.4 in.).
- Flower: Corolla regular (actinomorphic), creamy white, 1–2 cm (0.4–0.8 in.) broad; petals 5, obovate, approx. 1 cm (0.4 in.) long. Sepals 5. Stamens 5. Gynoecium composed of 3 fused carpels. Flowers solitary terminating branches.
- Leaves: Dense at base, stalkless, overwintering. Blade linear–narrowly obovate, round-tipped, with entire margins, leathery, rigid, shiny.
- Fruit: Ovoid, approx. 4 mm (0.16 in.) long capsule.
- Habitat: Windy and dry tops on fell tundra, bare patches of gravel, rocky outcrops.
- Flowering time: June–August.
Lapland’s vegetation doesn’t put on much of a show for the winter traveller. Even on a skiing trip, however, there is at least one fell plant waiting to be discovered, and it is perhaps the most important one of all. Diapensia grows in places that the traveller might stop for a coffee and to admire the rugged view: snowless ridges and wind-whipped places in the tundra. It is rare for a plant to be able to survive the force of the Lapland winter without snow cover, and most of the land is blanketed anyway, but diapensia has adapted amazingly well to the harsh conditions: its root buries itself deep in the land and anchors itself firmly. Its stem is short and branching, its leaves hard, wax-covered and tightly packed against one another protecting the stem. Diapensia’s leaves are very long-lived, and even dead leaves absorb the heat of the sun in the tuft and provide nutrition for the plant in otherwise barren soil. Its dense, tufted growing form is unique among Finland’s flora: the whole plant is super-hardy and can withstand frost and drought. It has even survived exposure to -58 degrees centigrade.
Diapensia’s structure is also useful during Lapland’s short summer. The wind is forever blowing on the tundra but it is more hushed close to the ground and the sunshine is enough to warm up the thin layer of air. Insects also fly close to the ground, so it is not a good idea for flowers to grow high. There are not many pollinators on the fells so diapensia’s flowers are large and showy despite the plant’s relatively modest size. The species invests a lot in seed production as it doesn’t seem to spread vegetatively. Its small seeds spread in winter storms and spring melt-water, and some of them reach suitable ridges, some wind up down in the valleys. The seeds usually only germinate on bare gravel or otherwise open places, and individual plants can be found on rocky river banks too in the lower tundra. Diapensia grows on the Lapland fells from Pallas to Saariselkä, but it doesn’t appear on more southern fells.