Sagittaria graminea |
Sagittaria platyphylla |
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grass-leaf arrowhead, grassy arrowhead, sagittaire a feuilles de graminees |
delta arrowhead |
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Habit | Herbs, perennial, to 100 cm; rhizomes coarse; stolons absent; corms absent. | Herbs, perennial, to 150 cm; rhizomes absent; stolons present; corms present. | ||||||||
Leaves | submersed or emersed; submersed leaves phyllodial, angled abaxially, flattened adaxially, 6.4–35 × 0.5–4 cm; emersed with petiole triangular, 6.5–17 cm, blade linear to linear-oblanceolate, 2.5–17.4 × 0.2–4 cm. |
submersed and emersed; submersed sessile, phyllodial, flattened, to 26 × 0.5 cm; emersed with petiole ± triangular, 21–70.5 cm, blade linear-ovate to ovate, 4.6–16.4 × 0.7–6.1 cm. |
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Inflorescences | racemes or panicles, of 1–12 whorls, emersed, 2.5–21 × 1–8 cm; peduncles 6.5–29.7 cm; bracts connate more than to equal to ¼ total length, broadly subulate to lanceolate, 20–50 mm, coarse, not papillose; fruiting pedicels spreading, cylindric, 0.5–5 cm. |
racemes, of 3–9 whorls, emersed, 2.5–10 × 2–4.5 cm; peduncles 22–60 cm; bracts connate more than ¼ total length, lanceolate, 3–5.5 mm, delicate, not papillose; fruiting pedicels spreading to recurved, cylindric, 0.5–3 cm. |
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Flowers | to 2.3 cm diam.; sepals recurved to spreading, not enclosing flower; filaments dilated, shorter than anthers, pubescent; pistillate flowers pedicellate, without ring of sterile stamens. |
to 1.8 cm diam.; sepals spreading to recurved, not enclosing flower or fruiting head; filaments dilated, longer than anthers, pubescent; pistillate pedicellate, without ring of sterile stamens. |
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Fruiting | heads 0.6–1.5 cm diam.; achenes oblanceoloid, without abaxial keel, 1.5–2.8 × 1.1–1.5 mm, beaked; faces not tuberculate, abaxial wings 0–1, ± entire, glands 1–2; beak lateral, erect, 0.2 mm. |
heads 0.7–1.2 cm diam.; achenes oblanceoloid, not abaxially keeled, 1.2–2 × 0.8–1.2 mm, beaked; faces tuberculate, wings absent, glands absent; beak lateral, horizontal to erect, 0.3–0.6 mm. |
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2n | = 22. |
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Sagittaria graminea |
Sagittaria platyphylla |
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Phenology | Flowering summer–fall. | |||||||||
Habitat | Streams and lakes | |||||||||
Elevation | 0–900 m (0–3000 ft) | |||||||||
Distribution |
AL; AR; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WA; WI; WV; NB; NF; NS; ON; PE; QC; West Indies (Cuba)
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AL; AR; FL; GA; IL; KY; LA; MO; MS; OH; OK; PA; TN; TX; WV; Mexico (Nuevo León Mexico, sw Mexico); Central America (Panama)
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Discussion | Seven varieties of Sagittaria graminea have been recognized, i.e., var. graminea, var. platyphylla Engelmann, var. teres (S. Watson) Bogin, var. weatherbiana Fernald, var. cristata (Engelmann) Bogin, var. chapmanii J. G. Smith, and var. macrocarpa (J. G. Smith) Bogin (C. Bogin 1955). We accept only one infraspecific rank, i.e., subspecies. Consequently, we have made the appropriate combinations. We accept all of the taxa accepted by Bogin at the varietal level. At specific level we accept Bogin’s var. platyphylla, var. teres, and var. cristata and at subspecific level his var. graminea, var. chapmanii, and var. weatherbiana. Sagittaria graminea var. macrocarpa actually is synonymous with var. graminea (E. O. Beal 1960b). We therefore are following Beal in recognizing var. macrocarpa sensu Bogin as S. fasciculata. We also accept var. platyphylla, var. teres, and var. cristata at the specific level, leaving only three subspecies. These subspecies can be separated by the branching of the inflorescence and the length of pistillate pedicels. Subspecies 3 (3 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Sagittaria platyphylla has been accepted at the variety level, i.e., Sagittaria graminea var. platyphylla (C. Bogin 1955; J. W. Wooten 1973; E. O. Beal et al. 1982). After studying dozens of populations in the field from much of its range and hundreds of herbarium specimens, we have concluded that this taxon should be recognized at the specific level instead, a conclusion supported by cladistic analyses of morphologic characters (R. M. Kortright 1998) (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 22. | FNA vol. 22. | ||||||||
Parent taxa | ||||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | S. graminea var. platyphylla, S.. mohrii | |||||||||
Name authority | Michaux: Flora Boreali-Americana 2: 190. (1803) | (Engelmann) J. G. Smith: N. Amer. Sagittaria. 29. (1894) | ||||||||
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