Hosta Black Onyx will form a medium sized mound of 36 - 46 cm in height with a spread of up to 80 cm at maturity. A G Heemskirk introduction noted for it shiny green, almost black coloured leaves with gently wavy margins. In June - July it produce scapes of up to 75 cm with pale purple flowers. It should be grown in dappled shade and it is slug resistant.