| Family | Scientific Name | Common Name | Habitat | Distribution | Image |
|---|---|---|---|---|---|
| Juncaginaceae | Triglochin maritima | Northern Arrowgrass | Brackish coastal habitats and inland bogs. | Circumboreal, south in North America to New Jersey, Ohio, Nebraska, New Mexico, Mexico (Baja California, Baja California Sur, Chihuahua, México); also Patagonia. Reports from Delaware and Maryland are based on misidentifications; no specimen could be located for Bucks County, Pennsylvania. |  (c) Ward, Scott G |
| Juncaginaceae | Triglochin palustris | Slender Arrowgrass | Marshes, rich fens, alkaline meadows and shores. | A circumboreal species, south in America to Maine, New York, nw. Pennsylvania (Erie County; S. Grund, pers. comm., 2023), s. Ohio, c. Indiana, c. Illinois, Iowa, Nebraska, New Mexico, Arizona, California, Mexico, and South America. |  (c) Ward, Scott G |
| Juncaginaceae | Triglochin striata | Southern Arrowgrass | Brackish to nearly freshwater marshes. | The species has an extensive range, occurring in tropical Central and South America, West Indies, Africa, and Australia; in North America, it ranges from Maryland and Delaware (extirpated) south to s. Florida and west to Louisiana, and also on the west coast in California and Oregon. |  (c) Fleming, Gary P. |