Palm-like plant. Succulent. The greatly swollen trunk base and the recurving, narrow leaves are certain identification. With age, the trunk eventually develops a few branches. Ponytail can get up to 30' tall, and the base up to 12' across, but houseplants generally remain less than 6 or 8' tall. The plant looks a little like a palm, and a little like a big onion sitting on the ground with a single stalk growing up and sporting a parasol of drooping, strap-like leaves.Plants are dioecious, meaning only female plants will produce seed.
Ponytail makes a large and handsome houseplant, doing well even in rooms with air conditioning as long as it has bright light. It's a good specimen plant for a rock garden in a dry, warm climate.
Closely related species - Beaucarnea guatemalensis.