This is an rare and beautiful tulip. Crisp white triangular flowers come with raspberry stripes on the outside and a blackcurrant heart on the inside. Height is 30cm (12"). 

Tulipa Clusius is sterile, spreading by way of underground stolons. If yours is not, it isn't Tulip Clusiana.

Although rare today, it has been grown since the 17th century. In fact, it is named after Carolus Clusius, the great botanist who first introduced tulips to The Netherlands in the late 16th century. Originally, it comes from Iran and Afghanistan, where it is still found in the wild, albeit in different forms.