Sagittaria L. (Alismataceae)

Sagittaria is represented by seventeen taxa in North Carolina. Only S. fasciculata is listed at the federal level (Fed E, S1 G2). Four additional species are state listed: S. chapmanii (State T, S1 G3?), S. isoetiformis (State T, S2 G4), S. macrocarpa (State T, S2 G2), and S. weatherbiana (State E, S2 G3G4). All species listed fall into a group of taxa exhibiting leaves linear to lanceolate, not sagittate or cordate. Sagittaria fasciculata is the only linear-lanceolate-leaved species in the genus occurring in the mountains in North Carolina. Additional species of conservation concern tracked by NHP are S. filiformis (State SR-P, SH G4G5) and S. spatulata (State SR-P, SH G4), both historical in the state.

Federally listed taxon—
Sagittaria fasciculata (Fed E, State E | S2 G2)

Habitat. "Seepage areas with very low water flow and no stagnation; soils are sandy loams overlain by muck 10-24 inches deep; some shade is beneficial" (USFWS).

Range. Endemic to western North and South Carolina.

Additional resources. NHP | Recovery plan | 5-year review

Key to Sagittaria in North Carolina

Key adapted from Haynes and Hellquist (2000 [FNA]) and Weakley (2008). Photos by Krings, unless indicated otherwise. Line drawings from Britton & Brown (1913), unless indicated otherwise. Maps courtesy of USDA PLANTS and the North Carolina Natural Heritage Program.

1. Leaf blades sagittate or cordate...[S. australis, S. calycina, S. engelmanniana, S. filiformis, S. latifolia, S. montevidensis, S. spatulata]

1’. Leaf blades linear or lanceolate, or modified as linear, bladeless phyllodia, often spongy in texture...2.

2. Stalks of the pistillate flowers reflexed in fruit, often stout; filaments glabrous...[S. calycina, S. filiformis, S. platyphylla, S. spatulata, S. subulata]

2’. Stalks of the pistillate flowers ascending or spreading in fruit, not notably stout; filaments roughened with minute scales (except glabrous in S. fasciculata)...3.

3. Filaments narrower than the anthers, diameter changing little from base to summit...[S. engelmanniana, S. lancifolia]

3’. Filaments as broad or broader than the anthers, either distinctly dilated toward the base OR thickened throughout...4.

4. Plants with corms and/or stolons, lacking coarse rhizomes...5.

5. Blades of emersed leaves lanceolate, narrowly spatulate, > 5 mm wide...S. fasciculata*

5’. Blades of emersed leaves linear (< 3 [–4] mm wide) or phyllodial...6.

6. Achenes 1.5–2.0 (–2.5) mm long; inflorescence bracts connate for > 50% of length...S. isoetiformis

6’. Achenes (2.2–) 2.4–3.0 mm long; inflorescence bracts connate for < 40% of length...S. macrocarpa

4’. Plants with coarse rhizomes, lacking corms and stolons...7.

7. Inflorescence paniculate (branched at the base in at least some plants of a population)...S. chapmanii

7’. Inflorescence racemose...8.

8. Larger phyllodia to 1 cm wide, apices acute...S. graminea

8’. Larger phyllodia 0.8–2.5 cm wide, apices blunt (rarely acute)...S. weatherbiana