A steady stream of horticultural and garden design accolades can be found if one scans the gardening literature for black mondo grass or black turf-lily. Given that it’s one of the few plants I personally grow in my little balcony garden, the praise must be well-deserved!
It is a Great Plant Pick, a Missouri Botanical Garden Plant of Merit, and a Royal Horticultural Society Award of Garden Merit plant. Perhaps not an honorific, but something that alludes to both its dependability and boldness, was its use to form the black ring in horticultural displays celebrating the 2012 Summer Olympic Games (see: Ophiopogon planiscapus ‘Nigrescens’ at Kew).
Here’s a video, but you’ll have to use your imagination–initial plantings were done with pansies for the black ring, but as these faded they were replaced with Ophiopogon planiscapus ‘Nigrescens’ (or else it filled in the spaces as the pansies declined, as I think I can spot young plants of black mondo grass).
Despite the common names, it is neither a grass (members of Poaceae) nor a lily (Lilium within Liliaceae). It is actually more closely related to Asparagus, as it is in the Asparagaceae. And, more curious, this more-or-less woodland species of open slopes in its native Japan belongs to the same subfamily (Nolinoideae), as the (primarily Mexican and Texan) desert-loving species of Nolina.