For those of who react allergically to grass, being able to identify one species from another is not only helpful, but in serious cases it can be potentially life saving as one thus knows when one is in the presence of a species that may cause a particularly severe respiratory reaction. The challenge is that the grasses are one of the trickiest of all the plant families to get sorted, and the sheer number of them here in Oregon and Washington – native and introduced – approaches four hundred when subspecies and varieties are included.