This is a silver variety of the Sansevieria trifasciata (common name: Mother's-in-Law Tongue, Snake Plant; Family: Agavaceae) planted at the Silver Garden.The white flowers look inconspicuous and I would have missed it if I wasn't observant enough. Anyway, this plant does not like too much water, otherwise it would rot from the base up. 2 links are shown below for reference:
