This gorgeous black flowered clone is one of the very darkest 
irises grown, although the flower colour is in fact a very deep 
violet that appears black, the falls having an exquisitely delicate
 golden tracery of veins near the centre. This solid clump-forming, 
rhizomatous perennial has upright, strap-like, grey-green leaves, 
and is truly one of the nearest flower colours to black it is possible
to grow although seedlings may vary.

Iris Black Knight {Iris chrysographes} Stunning Ornate Blooms | Cutting Favorite | 5 seeds Free Shipping!

Iris chrysographes, called the Black Knight, is found naturally in 
Europe. This Iris has dark and sumptuous flowers. The adult plant is
about 50 cm tall. The flowers consist of 3 sepals and 3 petals. They 
are about 3 inches in diameter, black or dark brown and have dark 
purple markings. They are very fragrant. Flowers appear on tall stems. 
Plants bloom from spring to summer. The plant is self-fertile. Iris 
chrysographes develops narrow, sword-shaped greyish green leaves rising 
1 foot tall or more. The plant spreads by means of its modified stems, 
rhizomes, which are located below the soil surface. Hardiness zones 4-9,
(-32øC/-25øF, -5øC/25øF) in winter. It is less resistant to cold than 
other Iris. It requires full sun to light shade. In grown in pot, bring 
the plant inside in winter. In the wild, it grows in rocky spots or sunny 
fields. Iris chrysographes grows in fresh and humus soil. Requires partially
moist soil; don't overwater. It can grow in full sun or light shade. It loves 
a soil covered with organic matters.