thumb|200px|Potatoes are observed by Europeans for the first time during two Spanish expeditions in the Viceroyalty of Peru (pictured is a 1603 illustration of by Carolus Clusius's of "Papas Peruanorum"). Year 1537 (MDXXXVII) was a common year starting on Monday of the Julian calendar.
thumb|200px|Potatoes are observed by Europeans for the first time during two Spanish expeditions in the Viceroyalty of Peru (pictured is a 1603 illustration of by Carolus Clusius's of "Papas Peruanorum"). Year 1537 (MDXXXVII) was a common year starting on Monday. of the Julian calendar