Common rock-rose

The common rock-rose (Helianthemum nummularium) is not a rose. The first part of its botanic name means “sunflower”, but it is not a sunflower either! However, its flowers do not open at night or in dull weather, so in one sense “sunflower” is an apt description.

The common rock-rose grows in rocky places, and also scrub and grassland, in England, Wales and southern Scotland.

It sends up branching shoots from a woody base. Those that grow upright reach a maximum height of 12 inches (30 centimetres) but others trail along the ground and may root themselves to form new plants. The narrow leaves grow in pairs at intervals along the stem, each leaf having a pair of tiny stipules at its base and dense white hairs on the underside.

Yellow buttercup-like flowers appear from June to September, giving rise to globe-shaped fruit that have a hairy casing. The flowers have no scent and do not produce nectar, although they still manage to attract insects. However, they are largely self-pollinating, this taking place when the flowers close up and the pollen on the stamens in pushed on to the style.

The flowers are delicate and will fall off if the plant is disturbed. 

© John Welford