Several years ago, we received plants from India as Colocasia antiquorum. One exceptional clone was later christened Colocasia 'Coal Miner'. In appearance, Colocasia 'Coal Miner' looks like a larger version of Colocasia 'Illustris' except for emerging 2 months earlier (late March in NC), and not spreading underground as vigorously as Colocasia 'Illustris'. The black leaf pattern is similar to Colocasia 'Illustris', but the background leaf color is quite different (dark olive vs. medium green) and the emerging new leaves have a stunning velvet patina. For us, Colocasia 'Coal Miner' tops out at 54" tall, while Colocasia 'Illustris' only reaches 40". I think you will agree that Colocasia 'Coal Miner' is worth excavating a new hole.