| Hosta | Blackjack |
| Status | registered |
| Originator(s) | Clarence Owens 1990 |
| Origin | sieboldiana 'Mira' x sieboldiana |
| Size category | large |
| Plant height x width | 75x180 cm (30x71 in.) |
| Leaf length x width | 38x36 cm (15x14 in.) |
| Vein pairs | 17-19 |
| Leaf color | blue-green>dark green |
| Variegation | |
| Leaf | very corrugated, thick, unruly |
| Petiole | |
| Scape | |
| Scape height | |
| Flower | white |
| Flower length | |
| Fragrant | |
| Flowering period | July |
| Fertile | |
| Pod | |
| Ploidy | |
| Patents | |
| Info | ='Black Jack'. The sensation of the 1999 AHS national convention. Large rounded black-green, much darker than 'Black Beauty'. Arching leaves. Emerges blue-green, turning dark green by mid-summer; heavy texture; rugose. Somewhat unruly in appearance. Seedling of 'Mira' and sieboldiana, large rounded black-green, much darker than 'Black Beauty'. 24" in height with arching leaves 13.5" by 15.5" in length. It's large size, corrugation, and blackish green color give 'Blackjack' a high level of distinction. |
| Sports | |
| Progeny | |