The tank in the lily house built in 1851 by Professor Charles Daubeny, Keeper of the Garden at the time, is the oldest existing part of the glasshouses. Tropical water lilies grow in boxes in the tank, including the hybrid "Nymphaea × daubenyana" named in honour of Professor Daubeny in 1874. Also growing in the house are economic plants including bananas, sugar cane, and rice, and the papyrus reed, "Cyperus papyrus", a native of river banks in the Middle East. Flowering high in the glasshouse is the yellow-flowered "Allamanda cathartica".