I reluctantly left the Long-tailed Tits to their labours and headed up though the woods towards the summit.
Emerging from the shelter of the trees near the summit of the hill I was confronted by a chilly breeze and on another day would have headed for the more sheltered side, but I wanted to see the Rockroses, which are at their best and most prolific on the exposed limestone cliff on this side. Happily the reward was well worth putting up with a bit of discomfort for; the sunshine yellow flowers on the edge of the cliff and cascading down the rocky hillside were spectacular.
The stiff breeze made focusing on the flowers in the following photographs a bit tricky though. The Latin name Helianthemum translates as sun flower, which refers to the flower’s habit of opening up on sunny days and closing on sunless ones. Being very sunny today there was a profusion of blooms but those out in the open were waving about, so I tried for ones in the shelter of rocks which were then shaded.
There are two species of Rockrose found here; one is the Common Rockrose –Helianthemum nummularium and the other is a species more common to the Mediterranean than the UK, the Hoary Rockrose Helianthemun canum, which is one of the specialty plants of this reserve.
The Common Rockrose is an evergreen plant, an undershrub, usually prostrate and spreading. The small leaves are a dark grey-green above and grey-white and woolly-hairy beneath. Flowering from April-July, it is common on chalk downs and an occasional plant in other types of grassland, but always on dry and base-rich soil.
The flowers of the native Rockrose are usually bright sunshine yellow, but may also be darker gold or even pale orange. Flowers are 12-20mm across, with 5 slightly crinkled petals. Each flower last only a day, but there are many of them. In the flower centre is a tight cluster of stamens.
Common Rockrose is a good provider of nectar for various species of bee and is also the foodplant of several species of moths and butterflies such as the Brown Argus, Green Hairstreak and the rare Silver-studded Blue. Many of the flowers I looked closely at today were playing host to at least one, usually more tiny little beetles.
Hoary Rockrose – Helianthemum canum (L.) Baumg
As I already mentioned, the Hoary Rockrose is one of the specialty plants growing on Bryn Euryn and its major British stronghold is located just a few miles away on the Great Orme in Llandudno. The plant is restricted to Carboniferous limestone. It is found on rocky outcrops and on the face of scars and cliffs, often on the upper parts of outcrops and in sparse vegetation on shallow soil near the edges of cliffs. It can be very abundant on steep, rocky, exposed, often south to west-facing sites, of 0-540m, which are prone to summer drought, which fits the location in which plants are most prolific here on the Bryn.
H. canum is a shrubby, mat-forming perennial. Plants flower freely and set abundant seed unless they are subjected to particularly heavy grazing. There is no specialised means of dispersal. Seeds produced in one summer germinate gradually over a long period but the successful establishment of seedlings requires a period of damp weather long enough for young plants to develop a root system which will withstand subsequent drought (Griffiths & Proctor 1956).
The flowers are smaller than those of the Common Rockrose, just 8-15mm across, but there are many more of them.
There are five slightly crinkled petals and at the centre of each flower there is a crowded cluster of golden stamens.
Factual extracts are from : The Online Atlas of the British and Irish Flora http://www.brc.ac.uk/plantatlas/index.php?q=plant/helianthemum-oelandicum