Saxifraga tridactylites, the rue-leaved saxifrage or "nailwort", is a species of plant in the family Saxifragaceae.
Rue-leaved saxifrage is an annual plant with distinctive, trilobed, fleshy leaves and red stems. These stems, the leaves and the sepals are covered in numerous sticky glands.
Most genus Saxifrage plants are perennials in cold, mountainous areas, so as an annual that grows in low-lying areas, rue-leaved saxifrage is an exception. It has been developing its own direction for a long time, and it has many special features which are a consequence of the extremely quick development of an individual plant. The species is probably native to the Mediterranean climate, which has produced equally quickly developing and quickly withering annuals.
Rue-leaved saxifrage grows in the south-west of Finland. Its typical habitat is bird rocks, but the species is not needlessly demanding as long as the soil is alkaline and nitrogenous and sunny, with not too much shade from neighbours. It often grows on rocks that have a thin layer of soil and cracks in rocks alongside other small annuals. Rue-leaved saxifrage flowers early in the spring, ripens its seeds quickly and completely withers. It is completely dependent on its seed production and for that reason, for safety’s sake, it is probably mainly self-pollinating. The seeds sprout at the end of the same summer and form a basal rosette by the autumn, so the species is an autumn annual.
This plant is useful.