Sagittaria engelmanniana |
Sagittaria ambigua |
|
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acid-water arrowhead, Engelmann's arrowhead |
Kansas arrowhead |
|
Habit | Herbs, perennial, to 70 cm; rhizomes absent; stolons present; corms present. | Herbs, perennial, to 90 cm; rhizomes absent; stolons present; corms present. |
Leaves | emersed; petiole triangular, 10–40 cm; blade sagittate, 4.5–10 × 0.2–2 cm, basal lobes ± equal to remainder of blade. |
emersed; petiole triangular, 15–54 cm; blade lanceolate to ovate, 5–20 × 1–10.5 cm. |
Inflorescences | racemes, of 2–4 whorls, emersed, 5–14 × 2–4 cm; peduncles 20–38 cm; bracts distinct or if connate, then less than ¼ total length, lanceolate, 5–25 mm, not papillose; fruiting pedicels spreading, cylindric, 1.5–3.5 cm. |
racemes, rarely panicles, of 2–11 whorls, emersed; bracts scarcely connate proximally, linear to lanceolate, 10–30 mm, delicate, not papillose; fruiting pedicels spreading to ascending, cylindric, 1.5–3.5 cm. |
Flowers | to 30 mm diam.; sepals recurved to spreading, not enclosing flower or fruiting head; filaments linear, longer than to equal length of anther, glabrous; pistillate pedicellate, without ring of sterile stamens. |
to 23 mm diam.; sepals recurved, not enclosing flower or fruiting head; filaments linear, shorter than anthers, glabrous; pistillate pedicellate, without ring of stamens. |
Fruiting | heads 1–1.8 cm diam.; achenes cuneate to obovoid, without abaxial keel, 2.4–4 × 1.5–3.8 mm, beaked; faces not tuberculate, wings 1–3, ± entire, glands 1–2; beak lateral, obliquely ascending, (0.7–)1–2.1 mm. |
heads 0.8–1.2 cm diam; achenes cuneate-obovoid, abaxially keeled, 1.5–2.1 × 0.8–1.5 mm, beaked; faces not tuberculate, wings 0–1, ± entire, glands absent; beak lateral, horizontal or incurved, 0.1–0.2 mm. |
2n | = 22. |
|
Sagittaria engelmanniana |
Sagittaria ambigua |
|
Phenology | Flowering late spring–summer (Jun–Sep). | Flowering spring–summer (Apr–Sep). |
Habitat | Acid waters of ponds, lakes, bogs, and streams | Pond and lake shores, shallow water, ditches, and damp areas |
Elevation | 0–1100 m (0–3600 ft) | 100–1000 m (300–3300 ft) |
Distribution |
AL; CT; DE; FL; GA; MA; MD; MS; NC; NJ; NY; PA; RI; SC; VA; ON
|
IL; IN; KS; MO; OK |
Discussion | Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | ||
Sibling taxa | ||
Name authority | J. G. Smith: Memoirs of the Torrey Botanical Club 5: 25. (1894) | J. G. Smith: N. Amer. Sagittaria. 22, plate 17. (1894) |
Web links |