Nick Upton / Hyssop-Leafed Mountain Tea / Ironwort (Sideritis hyssopifolia) flowering on a mountain slope in a limestone rock crevice, Covadonga, Picos de Europa, Asturias, Spain, August.

Nick Upton / Mountain ironwort/ White sage / Mountain tea (Sideritis dasygnaphala / Leucophae dasygnaphala) a Gran canaria endemic, flowering in volcanic uplands, Gran Canaria, May.

Nick Upton / Gran Canaria endemic plants, Mountain ironwort (Sideritis dasygnaphala / Leucophae dasygnaphala) and Aeonium / Tree houseleek (Aeonium simsii) growing among volcanic rocks within. Gran Canaria UNESCO...