I originally thought this was a bamboo, but was told that it may be a type of ornamental grass instead. Does anyone have any idea if that is true, and if so, what species it is?
It looks like Ravenna Grass (Saccharum revennae). You'll know for sure, very soon, as it will send up very tall flower spikes...12 feet plus, and get gigantic plumes on top of them.
It looks like Miscanthus sinensis, 'Gigantea' to me.