COUNTRYSIDE COUNCIL FOR WALES
National Grid reference: SH586815
Total Area: 17.1 ha
Bwrdd Arthur, a small flat‑topped Carboniferous Limestone hill reaching an altitude of 160m, is designated for its botanical interest. It is one of the larger and more diverse limestone sites in West Gwynedd. A number of plant communities are represented including limestone grassland, calcareous heath characterised by the presence of heather Calluna vulgaris, bell heather Erica cinerea and western gorse Ulex gallii and scrub with stands of common gorse Ulex europaeus, elder Sambucus nigra, hawthorn Crataegus monogyna, blackthorn Prunus spinosa and bramble Rubus. The limestone grassland includes characteristic species such as common rockrose Helianthemum chamaecistus, pale St. John's‑wort Hypericum montanum, long‑stalked crane's‑bill Geranium columbinum and and meadow oat‑grass Avenula pratensis. The limestone exposures support the nationally rare species, hoary rockrose Helianthemum canum and ivy broomrape Orobanche hederae, whilst a number of uncommon bryophyte species occur on its south‑facing slopes including Bryum canariense, B.elegans and Isothecium striatulum.