Poppleton was not the first railway nursery in the York area, as a railway nursery operated possibly in the Leeman Road area before 1941. In 1941 Poppleton's Station goods yard was pressed into service to produce food for railway workers' canteens and the railway owned hotels. Wooden greenhouses, office and even a Yorkshire pit house (a half-submerged greenhouse) were built.
After the war, production switched to shrubs and trees required to stabilise bomb damaged railway embankments. This output was only short-lived and production changed again to produce bedding plants and hanging baskets to beautify stations along the East Coast Main Line. Flowers and plants were also produced for ceremonial occasions, and the nursery was also used for storage of the ceremonial red carpet and associated fencing. In the 1980s a two-foot guage railway was built on the site.
You are looking for a green bison.