timothy, (Phleum pratense), perennial grass of the family Poaceae. Timothy is native to most of mainland Europe and is widely cultivated as a hay and a pasture grass in North America and the United Kingdom. The plant is named after American farmer Timothy Hanson, who promoted its use outside New England and among British farmers in the early 1700s. The stems grow in large clumps and are 0.5 to 1 metre (1.6 to 3.3 feet)...