Yucca

Yucca is a genus of perennial shrubs and trees in the family Asparagaceae, subfamily Agavoideae. Its 40–50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flowers.

Place in full light, water freely during the growing season from April to September and apply a balanced liquid feed fortnightly. During winter don't feed and water sparingly allowing the surface 5cm of compost to dry out between watering, then water thoroughly, making sure that surplus water drains through the pot.
Approximately 20" tall