| Family | Scientific Name | Common Name | Habitat | Distribution | Image |
|---|---|---|---|---|---|
| Hydrocharitaceae | Najas canadensis | Northern Naiad | Lakes, rivers, impoundments. | ME and MN south to VA, OH, and IN; in the west ID, WA, and OR (at least); also in n. Europe. |  (c) Léveillé-Bourret, Étienne - CC-BY-NC, permission granted to NCBG |
| Hydrocharitaceae | Najas filifolia | Narrowleaf Naiad | Lakes. | Sw. GA (Jones & Coile 1988) and s. AL to FL (Haynes in FNA 2000). |  © Nia Wellendorf |
| Hydrocharitaceae | Najas flexilis | Northern Naiad | Lakes, rivers, impoundments. | NL (Newfoundland) west to ON, south to CT, MI, and NE; also in the west from AB and SK south to OR and UT. |  (c) Steven, Daniel - C, permission granted to NCBG |
| Hydrocharitaceae | Najas gracillima | Slender Naiad, Bushy Naiad | Ponds, lakes, slow-moving streams. | NS west to MN, south to NC, AL, and MO; disjunct in CA (where likely alien). |  (c) Graeff, Alex - CC-BY-NC-ND, permission granted to NCBG |
| Hydrocharitaceae | Najas guadalupensis var. floridana | Lakes and streams. | S. GA and s. AL south to FL. |  (c) Bradley, Keith | |
| Hydrocharitaceae | Najas guadalupensis var. guadalupensis | Common Naiad, Southern Naiad | Lakes, rivers, impoundments. | ME to AB and WA, south to s. FL, TX, and CA, and south through Mexico, Central America, South America; West Indies. |  (c) Watson, Ryan - CC-BY |
| Hydrocharitaceae | Najas guadalupensis var. olivacea | Lakes, rivers. | QC, ON, and MB south to NY, IN, IL, and IA. |  (c) htrommer - CC-BY-NC | |
| Hydrocharitaceae | Najas marina | Holly-leaf Naiad | Brackish or calcareous waters. | Scattered in ne. and nc. North America; FL; sw. United States, nw. United States (Freeman & Pfingsten 2021), Mexico, Central America, and South America; West Indies; Eurasia. |  (c) ÖkopatóPál - CC0 |
| Hydrocharitaceae | Najas minor | Spinyleaf Naiad | Ponds, lakes, and reservoirs, particularly where eutrophic. | Native of Eurasia. This species is apparently a rather recent introduction to North America, now widespread in e. North America. |  (c) Spaulding, Dan - CC-BY-NC, permission granted to NCBG |
| Hydrocharitaceae | Najas wrightiana | Wright’s Naiad | Blackwater streams, sloughs, freshwater marshes. | S. peninsular FL; West Indies (Cuba); Mexico and Central America (Guatemala, Belize, Honduras). |  (c) Horn, Jay |