Michx.
Identity
Unique IDELEMENT_GLOBAL.2.148071
Element CodePMALI040A2
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderAlismatales
FamilyAlismataceae
GenusSagittaria
SynonymsSagittaria graminea ssp. gramineaSagittaria graminea var. graminea
Other Common Namesgrassy arrowhead (EN) Grassy Arrowhead (EN)
Concept ReferenceKartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic CommentsThis record is for Sagittaria graminea in the narrow sense recognized in Weakley et al. (2023), which excludes S. macrocarpa, S. chapmanii, and S. weatherbiana as distinct species. Kartesz (1994) recognized a broad treatment of Sagittaria graminea with these species accepted as varieties: var. macrocarpa, var. chapmanii, and var. weatherbiana, with var. graminea equivalent in concept to Weakley's S. graminea sensu stricto. FNA (vol. 22, 2000) recognizes three subspecies in S. graminea: ssp. chapmanii, ssp. weatherbiana, and ssp. graminea, in a broad sense (including S. macrocarpa).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-07-10
Change Date1984-08-13
Edition Date2025-07-10
Edition AuthorsN. Ventrella (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences81 - 300
Rank ReasonsSagittaria graminea is an aquatic forb occurring in shallow to deep waters of bogs, ponds, marshes, swamps, floodplains, and ditches of eastern North America, from Newfoundland, Labrador, and Ontario, Canada south to Florida, Texas, and Arizona in the United States, and the West Indies. It is considered introduced to Washington state. There are over one hundred estimated occurrences of this species in its native range, which are threatened by changes to water levels, invasive plant species, grazing by carp, and likely other threats in some places. Little is known about trends, but with a large range extent, abundant habitat, and broad habitat preferences, Sagittaria graminea is considered secure.
Range Extent CommentsSagittaria graminea occurs in eastern North America, from Newfoundland, Labrador, and Ontario, Canada, south to Florida, Texas, and Arizona in the United States, and the West Indies (Kartesz 1996, Weakley and the Southeastern Flora Team 2025). This species is considered introduced in Washington state (Giblin 2025). The native range extant was estimated to be over 7 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are more than one hundred occurrences in the native range (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025). However, due to different treatments of this entity, herbarium records and photo-based observations may not accurately reflect true abundance.
Threat Impact CommentsThreats to Sagittaria graminea are not well documented but include changes to water levels, invasive plant species, grazing by non-native carp, and likely other threats in some places (NatureServe 2025). There is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this taxon.