- Family: Stonecrop Family – Crassulaceae
- Growing form: Annual or biennial herb.
- Height: 5–10 cm (2–4 in.). Stem erect, branched from base, branches erect, tip curving downwards.
- Flower: Corolla regular (actinomorphic), (greenish) yellow, approx. 1 cm (0.4 in.) wide; petals five, 3–4 mm (0.12–16 in.) long. Sepals 5. Stamens 10. Gynoecium with separate leaves, pistils 5. Inflorescence a lax cyme.
- Leaves: Alternate, stalkless, sparse. Blade quite cylindrical, both sides flat, glabrous, fleshy, initially lime green, later often with reddish brown spots.
- Fruit: Cluster of 5 many-seeded, basally united follicles.
- Habitat: Rocks, precipices, hill slopes, meadows, walls, fell tundra.
- Flowering time: June–July.
Many of the stonecrops that grow in Finland are ornamentals that have escaped from gardens, and the habitat of Finland’s native species has changed as people transplant the plants into their gardens. Short-lived – annual or at most biennial – annual stonecrop is not really suited to rockeries, but its spread is however interestingly split in two.
Annual stonecrop grows here and there on the Åland Islands, coastal areas of south-west Finland and Uusimaa Province and in Kymenlaakso. There are more inland stands in southern and northern Häme, Satakunta and southern Savo. Apart from southern Finland there are also stands in Lapland, on the southern slopes of the large Enontekiö fells, and on e.g. Saana, Malla, Annjaloanji and Saivaara. In southern Finland the species demands acid soil, but even calciferous slopes in the north make suitable habitats. Finland is covered in bare rock and acid soil, but annual stonecrop’s habitat is limited by climate.
Annual stonecrop grows both on the coast and in the maritime climate of the north-west of Finland, and inland in the micro-climate of the big lakes. Annual stonecrop often withers and dies before the pleasant midsummer weather begins, so it is unable to exploit its ability to conserve water in its shoots – although perhaps this quality would not be needed in Finland’s wet climate anyway. In the case of annual stonecrop, its nature as a nectar plant seems to be inherited from its ancestors – but it no longer requires these properties.