Ravenea robustior
This photo above is in habitat taken by Phil Arrowsmith.

Ravenea robustior

This Ravenea species holds its leaves quite upright and is easily distinguished form many of the other species in this genus with this habit, it grows best in the full sun but will grow fine in a shaded situation, this palm needs little attention once established and seems to be quite drought tolerant, it likes a well-mulched garden bed and should be planted in a prominent area to appreciate the true beauty of this palm. It's a little slow growing in the subtropics but would probably grow faster in the full sun. Temps 2C to 40C. You could fertilize a few times a year but best burring the warmer months.