Asteraceae buttons close-up Cow Bitter flower gift Golden Buttons herb Mugwort perennial plant poison tanacetum tansy yellow England english field grass grasses Great Britain green leaf lush meadow natural nature stalk summer wild appearance black brightly-coloured carpeting-plants clump-forming clumps color coloration colored colorful colors colour coloured colourful colours common daisy-like drought-tolerant environmental-weed flowers garden flowers garden-escape gazania gazanias golden hardy introduced-species invasive lance-shaped-leaves low-growing orange plants prolific rapid-spreader resilient roadside-weeds South-African streaked tough vivid water-wise weed widespread wind-blown-seeds