dainty delicate dolomites flower fragile Italy least snowbell montane nature Primulaceae remote small snowbell Soldanella Soldanella minima tiny wild alpine droop drooping frilled hang hanging mountain natural pendant pendulant plant Ranunculaceae aggressive-grower allium-triquetrum Amaryllidaceae blooming blooms bulbous-flowering-plant edible fast-spreading flower-stalks flowering flowers garden green introduced invasive leaves Mediterranean-import onion-weed plants profusion stalks three-cornered-leek white