Leptinella squalida
Leptinella squalida is a species of flowering plant in the daisy family, native to New Zealand. Known as "brass buttons" for its yellow button-like flowers, it grows to about tall, spreading indefinitely via rhizomes. A cultivar with almost black foliage, L. squalida 'Platt's Black', is grown as an ornamental plant, particularly in rock gardens and in flowering lawns. References Anthemideae Flora of New Zealand