Ensete Ventricosum
This big banana, whose trunk can reach nearly a meter (3 ft.) in diameter, is a real botanical curiosity. The Abyssinian Banana is unbelievably fast growing, Native to the highlands of eastern Africa between 1500 and 3000 m, it prefers mild climates without extremes of temperature. It is very adaptable but does not like hot, humid, tropical conditions or temperatures much below freezing. It can be used as a summer bedding plant in cooler climates, otherwise, plant it straight into the ground in a sunny spot, and stand back.
First scarify the seeds with some sand paper and then soak them in lukewarm water for 48 hours. Sow them in sowing mix and let them germinate at around 25C. Germination can take several weeks to months. 
price is for 5 seeds