A tuberous hybrid that has proven to be fully hardy with us and which is still very rare in cultivation. We have read that ‘Torsa’ is a cross between B. grandis and an unidentified tuberous species from Bhutan. The plant superficially resembles B. grandis until it reaches full maturity and then it reaches extra-large dimensions. Leaves are large, thick and covered in soft hairs with the backs of the leaves having prominent, red veins. Also like B. grandis it produces bulbils in the leaf axils (only much larger) that fall to the ground and produce more plants. Comes into growth quite late in the season. Height 50 cm. Full to part shade in a sheltered position in moist, humus rich, well-drained soil with a winter mulch.