Callitriche pedunculosa |
Callitriche palustris |
|
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Nuttall's water-starwort |
callitriche des marais, spring water-starwort, vernal water-starwort |
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Stem | and leaf scales present. |
and leaf scales present. |
Leaves | connate at base, obovate-oblanceolate to spatulate, (2.2–)2.7–5.7 × 0.7–2 mm, 2+-veined. |
connate at base, ± linear, tapering strongly from near base or spatulate, 2.5–9 × 0.3–5 mm, 1+-veined. |
Inflorescences | bracts absent. |
bracts caducous, sometimes persistent. |
Pedicels | 0–5 mm in fruit. |
0–0.2 mm in fruit. |
Flowers | usually 1 staminate and 1 pistillate in 1 axil opposed by 1 pistillate, rarely both pairs at an axil with 1 staminate and 1 pistillate; styles loosely ascending or ± reflexed; pollen yellow. |
usually 1 staminate and 1 pistillate in 1 axil opposed by 1 pistillate; styles erect or spreading; pollen yellow. |
Schizocarps | 0.8–1 × 0.9–1.3 mm, shorter than wide; mericarps black, not swollen, winged throughout, wings curled, giving appearance of thickened margins, 0.06–0.15 mm wide. |
obovoid, usually widest distal to middle, 0.8–1.4 × 0.6–1.4 mm, longer than wide, sometimes as long as wide; mericarps black, not swollen, not winged, winged only at apex, or winged throughout but widest at apex, wings straight, 0.03–0.1 mm wide. |
2n | = 20. |
= 20. |
Callitriche pedunculosa |
Callitriche palustris |
|
Phenology | Flowering Feb–Jun(Sep–Oct). | Flowering May–Oct. |
Habitat | Seasonally wet sandy soils, in or shaded by woodlands. | Fast-flowing rivers and streams, backwaters, ditches, swamps, Sphagnum bogs, lakes, ponds, springs, seepages. |
Elevation | 0–100 m. (0–300 ft.) | 0–3600 m. (0–11800 ft.) |
Distribution |
AL; LA; MS; TX |
AK; AZ; CA; CO; CT; DE; IA; ID; IL; MA; ME; MI; MN; MT; ND; NE; NH; NJ; NM; NV; NY; OR; PA; RI; SD; TX; UT; VT; WA; WI; WY; AB; BC; MB; NB; NF; NT; NU; ON; PE; QC; SK; YT; SPM; Greenland; Mexico (Chihuahua, San Luis Potosí); Eurasia [Introduced in Australia]
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Discussion | Callitriche nuttallii Torrey is an illegitimate, superfluous name that applies here. Torrey proposed it as a replacement for C. pedunculosa Nuttall based on the mistaken belief that the name by Nuttall was a later homonym of one by Arnott; the purported name by Arnott does not exist. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Callitriche palustris has been included on the Composite List of Weeds maintained by the Weed Science Society of America (http://wssa.net/wssa/weed/composite-list-of-weeds/); its inclusion seems unwarranted. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 17, p. 53. | FNA vol. 17, p. 53. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. palustris var. stenocarpa, C. palustris var. verna, C. stenocarpa, C. verna | |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 5: 140. (1835) | Linnaeus: Sp. Pl. 2: 969. (1753) |
Web links |
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