Cryptocoryne cordata var. siamensis "evae" has been grown in Australia for decades. Cryptocoryne evae is an old names that is now considered a synonym of Cryptocoryne cordata var. siamensis. This plant has much darker leaves in emersed culture compared to the submersed grown.
This is a cutting from a plant I got just over a year ago. Growing in a little peat and dirt in the bottom of a Moccona coffee jar. I removed the plastic seal from the lid to allow a little gas exchage and the jar sits on my window sill. I haven't lifted the lid for 6 months... low maintenance indeed and the plant appears happy.