Alopecurus geniculatus

History of Spread

Alopecurus geniculatus (Water Foxtail) is native to Eurasia, where it ranges from Northern Scandinavia to the Mediterranean, and west to the Russian Pacific Coast (Swedish Natural History Museum 2001). The status of this grass in North America is uncertain; but many authors have considered it a likely introduction. Gray (1848); referred to it as 'rare; introduced'; Fernald (1950) noted it as 'natzed from Eu.' (naturalized from Eurasia) and Gleason and Cronquist (1991) considered it 'a Eurasian or perhaps circumboreal sp., found throughout most of our range as an apparent introduction'. However; Hitchcock and Chase (1950) treated it as native, and Brown and Brown (1984) call it 'naturalized from the western states'. Alopecurus geniculatus was reported from dry ballast in New York by Brown (1881), but this was long after its first collections in North America. We have called this species cryptogenic, based on the contradictory assessments cited above.

Alopecurus geniculatus was found among MD herbarium specimens collected before 1753 (Brown et al. 1987); and was apparently rare but widespread in the Northeast from the early 1800's onward (Torrey 1823; Gray 1848). The first reported specimens from the Great Lakes basin were collected in 1882-1886 (Mills et al. 1993). Its present range is from Newfoundland to northern VA, west to MN, and apparently disjunct western populations from KS to BC, and south to CA (Fernald 1950; Harvill et al. 1992; Hitchcock and Chase 1950).

Alopecurus geniculatus was listed in early flora for Baltimore (Aikin 1837) but not Washington (Brereton 1831). The next published record from our region was in a 'marsh at the mouth of Hunting Creek' on the Potomac at Alexandria VA (Ward 1881). Specimens were collected from Hunting Creek (VA) and Oxen Run (MD) in 1876 and 1883, These are the only definite record of this species from tidal Chesapeake sites (US National Herbarium collections). It was not listed in Shreve et al. (1910). Other records are from 'wet meadows' (Aikin 1837); 'wet and grassy places' (US National Herbarium collections); 'banks and ditches and streams, rare' (Hitchcock and Standley 1919) 'Rare;...shallow water and wet soils; Dorchester County and D.C. area' (Brown and Brown 1984). In VA, it has been reported only from Arlington and Fairfax Counties (Harvill et al. 1992). Within the watershed, Alopecurus geniculatus occurs in PA, MD, VA, DC, and probably NY (Mills et al. 1993; Natural Resources Conservation Service 1998; Rhoads and Klein 1993).

Refrences- Aikin 1837; Brereton 1830; Brown 1881; Brown and Brown 1984; Brown et al. 1987; Fernald 1950; Gray 1848; Harvill et al. 1992; Hitchcock and Chase 1950; Hitchcock and Standley 1919; Mills et al. 1993; Natural Resources Conservation Service 1998; Shreve et al. 1910; Torrey 1823; Ward 1881; US National Herbarium collections

Invasion Comments