Little lovegrass, an annual species native to Europe, was not listed in the floras that describe the plants of Idaho and Washington. Twelve collections were made between 1984 and 1992 from four Idaho counties and six Washington counties. Those records extended the range of this species 450 to 1000 km northwest of populations reported in the literature. Approximately 600 km separated the furthest of the new collection sites, indicating widespread naturalization in those states. Eight of the collections were from roadsides, suggesting that human transport technology had a substantial influence on this plant's dispersal.

Two introduced windgrass species have become crop weeds in North America. Common windgrass is a major weed of winter cereals in Europe and was first documented in North America in the early 1800s. It is a weed of roadsides and waste areas in the northeastern United States and in winter grain fields of southern Ontario and Michigan. Interrupted windgrass was first reported in North America approximately 90 yr ago; it is adapted to more arid sites than common windgrass and is distributed predominantly in the northwestern U.S.A. During the past 10 to 15 yr, interrupted windgrass has adversely affected winter grain and grass seed producers in the Pacific Northwest due to additional control costs.