Common rockrose

Helianthemum nummularium

Helianthemum nummularium subsp. glabrum
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Malvales
Family:	Cistaceae
Genus:	Helianthemum
Species:	H. nummularium
Binomial name
*Helianthemum nummularium* (L.) Mill.

Helianthemum nummularium (known as common rock-rose) is a species of rock-rose (Cistaceae), native to most of Europe.

It is an evergreen trailing plant with loose terminal clusters of bright yellow, saucer-shaped flowers. In the flower centre is a tight cluster of orange stamens, which are sensitive to the touch, and spread outwards to reveal the tall stigma in the middle. The plant is common on chalk downs, and occasional in other grasslands, always on dry, base-rich soil. The wild species has yellow flowers, but garden varieties range from white through yellow to deep red.

Though the individual blooms are short-lived, the plant produces a mass of flowers through the summer. It needs a dry, sunny place, like a south-facing rockery or meadow. As the Latin name Helianthemum suggests, these are sun-flowers. This is a good nectar source for bees and there are several species of small beetle that feed on the foliage. Common rock-rose is also the food plant for the larvae of several species of moth and butterfly.

It flowers from May until July.

There are eight subspecies:

H. nummularium subsp. obscurum
Germany - Schwäbisch Fränkische Waldberge

H. nummularium subsp. obscurum
Germany - Schwäbische Alb

flower diagram

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Wikipedia