Cascade is dark green with elongated cones. It was developed at Oregon State University and became available around 1971. It's a flowery and citris-like type with slight grapefruit characteristics.
Bred and released by Washington State University in 1990, Centennial is a widely popular strain often refered to as the "super-Cascade". It can also be used for bittering purposes in your brews.
This strain was released in 1985 by the USDA breeding program in Washington State and is very high in alpha acid making it bitter. It has a spice and pine aroma when brewed making it a versatile strain.
Columbus is a descendant of Nugget that is high in alpha acid and is a primary strain for bittering. It is earthy and spicy in aroma with a hint of citrus. It is a moderate to high strain in alpha acid.
Made bye the USDA in Oregon, Nugget was released in 1983. It's very high in alpha acids making it a very bitter strain. It has an herbal woody type aroma and beers brewed with it tend to have good foam retention.