Source: Magness et al. 1971
Birdsfoot trefoil is a perennial, fine-stemmed, leafy legume that has become of increased importance in American agriculture in recent years. Introduced by chance from Europe, strains selected in this country are now of major importance as pasture and hay crops. It is hardy and adapted to areas of ample moisture supply from the Ohio and Potomac Rivers north into Canada and west to the edge of the Great Plains, also in humid parts of the Pacific States. The leaves are sessile along the stems, each with 5 linear to oval leaflets. Stems are decumbent unless in fairly dense stands, reaching 20 to 40 or more inches in length. The plant has a deep, branched root system and tolerates both wet and moderately dry conditions. It is unusual among legumes in that it does not cause bloat in cattle. Both as pasture and as hay it is highly palatable and nutritious. Harvested seed increased 6-fold from 1949 to 1959, and in the latter year was sufflcient to plant about 300,000 acres, according to census data.