Many catalogues list Eucomis autumnalis, but plants bearing this name have been widely mis-named for a great many years. What is normally supplied is the white-flowered fairly tender Eucomis zambesiaca.
But this is the true species and it is a really tough form with semi-erect green leaves and striking green-white blooms on a solid upright raceme of flowers, all topped by a green topknot. I've had this species in a pot in cold winters and it seems to motor through, growing in combination with other plants might help (a Zantedeschia in my instance).
It is a beautiful form, attracts butterflies and does not flop in any way, highly recommended!
Note that small pots are probably best grown-on before spending a winter outside.