Common rock rose
Helianthemum nummularium
Family · Cistaceae · Harmless
The commonest yellow flower of limestone mountain meadows, with five crumpled paper petals opening in the morning sun and falling by afternoon. Each flower lasts a day.
Uplands · Fields and pasture · Scrubland · Roadsides and waste ground
Also known asrock rose, sun rose
How to tell it
A creeping branched subshrub. Opposite leaves, oval or elongated, green above and white-haired beneath, with visible stipules at the stalk base. Golden yellow flowers two centimetres, in racemes of three to twelve, with many stamens in the centre. Almost always on limestone.
What it is confused with
No dangerous lookalikes known in the Iberian Peninsula.
What it is for
No use. It matters for a tracking reason: rock roses of this genus form mycorrhizae with truffles, and the Spanish name hierba turmera comes from that, because desert truffles were sought beneath them.