Sagittaria australis |
Sagittaria demersa |
|
---|---|---|
Appalachian arrowhead, longbeak arrowhead |
Chihuahuan arrowhead |
|
Habit | Herbs, perennial, to 130 cm; rhizomes absent; stolons present; corms present. | Herbs, annual, to 60 cm; rhizomes absent; stolons present; corms present. |
Leaves | emersed; petiole 5-winged, 19–85 cm; blade sagittate, 3–19 × 2.5–11 cm, basal lobes ± equal to remainder of blade. |
submersed, phyllodial, lenticular, to nearly terete, 12–53 × 0.3–0.7 cm; rare stranded plants without expanded leaf blades. |
Inflorescences | racemes, of 5–12 whorls, emersed, 10–29 × 3–5 cm; peduncles 25–105 cm; bracts distinct or if connate, then less than ¼ total length, lanceolate, 7–30 mm, papery, not papillose; fruiting pedicels spreading to ascending, cylindric, 0.3–2.3 cm. |
racemes, of 2–7 whorls, floating or emersed, to 16 × 4 cm; peduncles 13.5–28 cm; bracts connate more than ¼ total length, ovate to lanceolate, 1.5–2 mm, delicate, not papillose; fruiting pedicels spreading to reflexed in flower and fruit, cylindric, 1.5–6.5 cm. |
Flowers | to 3 cm diam.; sepals recurved to spreading, not enclosing flower or fruiting head; filaments cylindric, longer than anthers, glabrous; pistillate pedicellate, without ring of sterile stamens. |
1.5–5 cm diam.; sepals spreading in staminate, appressed to spreading in flower and fruit in pistillate, often enclosing flower or fruiting head; filaments dilated, longer than anthers, glabrous; pistillate pedicellate, without ring of sterile stamens. |
Fruiting | heads 1–2.2 cm diam.; achenes obovoid, without abaxial keel, 2.1–3.2 × 1.4–2.3 mm, beaked; faces not tuberculate, wings 0–2, ± entire, glands absent; beak lateral, strongly recurved, 4–17 mm. |
heads 0.4–0.6 cm diam; achenes oblanceoloid to obovoid, not abaxially keeled, 1.5 × 1 mm, beaked; faces not tuberculate, wings absent, glands absent; beak lateral, erect, 1.1 mm. |
2n | = 22. |
|
Sagittaria australis |
Sagittaria demersa |
|
Phenology | Flowering summer–early fall (Jul–Oct). | Flowering summer–fall. |
Habitat | Slightly basic to slightly acidic ponds, lakes, and swamps | Streams and lakes |
Elevation | 1–300 m (0–1000 ft) | 1500–2000 m (4900–6600 ft) |
Distribution |
AL; AR; FL; GA; IA; IL; IN; KY; LA; MD; MO; MS; NC; NJ; NY; OH; PA; SC; TN; VA; WV
|
NM; c Mexico |
Discussion | The name Sagittaria longirostra (Micheli) J. G. Smith has been misapplied to S. australis (J. G. Smith) Small (E. O. Beal et al. 1980). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Sagittaria demersa was known previously only from central Mexico. It is known in the United States from three recent collections taken in northern New Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Alismataceae > Sagittaria | Alismataceae > Sagittaria |
Sibling taxa | ||
Synonyms | S. longirostra var. australis, S. engelmanniana subsp. longirostra | |
Name authority | (J. G. Smith) Small: Flora of the Southeastern United States 45. (1903) | J. G. Smith: N. Amer. Sagittaria. 32, plate 15, figs. 1–4. (1894) |
Web links |