`blue rock bindweed` flower - convolvulus sabatius

africa african althaeoides arboretum arvensis august bind bindweed bloom blossom blue botanical botanist botany cantabrica cneorum convolvulaceae convolvulus erubescens flora florist flowers gallen garden glory ground leaf mauritanicus morning nature north outdoor park petals plants rock sabatius saint scammonia simulans solanales summer swiss switzerland tricolor valentinus violet virgatus weed