Native to New Zealand, brass buttons is a rhizomatous, mat-forming ground cover that grows to only 2” tall but spreads indefinitely by runners. It features button-like yellow flowers and fern-like green leaves. ‘Platt’s Black’ is a cultivar in which the unusual near black foliage is the real attraction. Delicate, fern-like leaves (to 2” long and to 1/2” wide) are obovate. Foliage will tolerate some foot traffic. Dark gold flowers bloom in early summer, and are followed by tiny fruit. Neither the flowers nor the fruit are considered to be particularly ornamental. Species plants were formerly known as Cotula squalida with the common name of creeping cotula.