Sold in 9cm and 1L pots. 
Voodoo lily.
 
An inflorescence is produced around late spring, from which a spathe emerges, producing a rather pungent odour, which lasts only a day or so. After several weeks a huge spiralling leaf emerges, growing up to 2' / 60cm across, from long mottled, green and black stems.
Care requirements: feeding is crucial (especially if growing in pots) in order for the corms to develop. Plant in dappled/partial shade or certainly out of intense midday sun, which may scorch the leaves. Provide a free-draining soil.
Hardy, but advisable to mulch during winter. Alternatively, tubers can also be lifted and dry stored over winter in a cool location.