Wildflower (forb) · Najadaceae
Southern waternymph
Najas guadalupensis · includes its varieties and subspecies
Southern waternymph is recorded as native to 42 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 619 counties of those states by USDA PLANTS.
Key facts · USDA PLANTS
Southern waternymph at a glance
- Native in
- 619 counties, across 42 states and territories
- Estimated cold hardiness
- Zone 3b PLANTS minimum temperature −36°F
- Mature height
- 1 ft PLANTS mature height
- Light and water
- Full sun (shade-intolerant) High water use
Estimated cold hardiness: zone 3b. PLANTS gives a minimum temperature of −36°F; zone 3b winters bottom out at −35°F, the coldest half-zone that stays within that limit.
Southern waternymph is recorded as native to 42 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 619 counties of those states by USDA PLANTS.
Counties where it is native
The 15 counties with the most ZIP codes among the 619 where it is listed.
Native counties by state
- Alabama 20 counties
- Arizona 2 counties
- Arkansas 5 counties
- California 23 counties
- Colorado 2 counties
- Connecticut statewide record
- Delaware 1 county
- District of Columbia 1 county
- Florida 39 counties
- Georgia 11 counties
- Illinois 64 counties
- Indiana 10 counties
- Iowa 3 counties
- Kansas 43 counties
- Kentucky 24 counties
- Louisiana 40 counties
- Massachusetts 6 counties
- Michigan 18 counties
- Minnesota 14 counties
- Mississippi 7 counties
- Missouri 40 counties
- Nebraska 14 counties
- Nevada 4 counties
- New Jersey 7 counties
- New Mexico 1 county
- New York 19 counties
- North Carolina 17 counties
- Ohio 4 counties
- Oklahoma 11 counties
- Pennsylvania 8 counties
- Rhode Island 1 county
- South Carolina 2 counties
- South Dakota 8 counties
- Tennessee 13 counties
- Texas 80 counties
- Utah 2 counties
- Vermont 1 county
- Virginia 19 counties
- Washington 3 counties
- West Virginia 1 county
- Wisconsin 22 counties
- Puerto Rico 9 counties
Growing traits
Values from the PLANTS characteristics record. “Not recorded” means PLANTS has no value; nothing here is estimated except the zone.
Growth
- Growth habit
- Forb/herb
- Duration
- Annual
- Mature height
- 1 ft
- Growth rate
- Moderate
- Growth form
- Single Crown
- Shape
- Prostrate
- Lifespan
- Not recorded
- Active growth period
- Summer
Light and water
- Shade tolerance
- Intolerant (full sun (shade-intolerant))
- Moisture use
- High water use
- Drought tolerance
- None
- Tolerance of waterlogged soil
- High
- Precipitation range
- Not recorded
Soil
- Soil textures
- Coarse, medium and fine
- pH range
- 5.2 to 9.6
- Lime (CaCO₃) tolerance
- High
- Salinity tolerance
- Medium
- Fertility requirement
- Medium
- Minimum root depth
- 2 in
Climate
- Minimum temperature
- −36°F
- Estimated cold hardiness
- Zone 3b and warmer
- Minimum frost-free days
- 130
- Fire tolerance
- None
Flowers, leaves and fruit
- Flower color
- Green
- Showy flowers
- No
- Bloom period
- Summer
- Foliage color
- Gray-Green
- Showy in fall
- No
- Keeps leaves
- No
- Fruit color
- Brown
Other
- Toxicity
- None
- Nitrogen fixation
- None
- Nursery availability
- No Known Source
- Family
- Najadaceae
- PLANTS symbol
- NAGU
Source & data date
- Source
- USDA NRCS PLANTS Database: county distribution records, native status and plant characteristics. CC0 (public domain dedication, per the data.gov catalog record).
- Kew’s World Checklist of Vascular Plants (WCVP): native or introduced status by state. CC BY 3.0.
- USGS US-RIIS (ver. 2.0): species listed as introduced are excluded. CC0.
- Citation
- USDA, NRCS. 2026. The PLANTS Database (https://plants.usda.gov, 11/04/2026). National Plant Data Team, Greensboro, NC USA.
- Govaerts R. (ed.) (2026). WCVP: World Checklist of Vascular Plants. Facilitated by the Royal Botanic Gardens, Kew. Data file dated 2026-06-04, http://sftp.kew.org/pub/data-repositories/WCVP/ (retrieved 2026-11-04). Paper: Govaerts R. et al. (2021) The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8, 215.
- Data date
- Retrieved from PLANTS on November 4, 2026; WCVP data file dated June 4, 2026.
- Scope
- Najas guadalupensis (PLANTS symbol NAGU), including 1 variety or subspecies folded into the species.
- Method
- A species is listed when it is recorded as native to the state in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in the county by USDA PLANTS. Species PLANTS labels both native and introduced are listed separately. Full method · All sources