Amaranthus viridis |
Amaranthus deflexus |
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green amaranth, slender amaranth, tropical green amaranth |
Argentina amaranth, deflexed amaranth, large-fruit amaranth, low amaranth |
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Habit | Plants annual, sometimes short-lived perennial in tropics and subtropics, glabrous. | Plants short-lived perennial or annual, pubescent in distal parts of plant or becoming glabrescent at maturity. |
Stems | erect, simple or with lateral branches (especially distally), 0.2–1 m. Leaves: petiole 1/2–11/2 as long as blade; blade rhombic-ovate or ovate, 1–7 × 0.5–5 cm, base rounded, cuneate, or attenuate, margins entire, plane, apex obtuse, rounded, or emarginate, mucronate. |
ascending or prostrate, profusely branched basally, radiating from rootstock, mostly 0.2–0.5 m. Leaves: petiole 1/2 as long as to equaling blade; blade rhombic-ovate or ovate to lanceolate, 1–2 × 0.5–1 cm, base tapering or cuneate, margins entire, plane or slightly undulate, apex subacute, obtuse, or retuse or shallowly emarginate, mucronulate. |
Bracts | of pistillate flowers ovate to lanceolate, 1 mm, shorter than tepals. |
of pistillate flowers linear, 0.5–1 mm, 1/2 as long as tepals. |
Inflorescences | slender spikes aggregated into elongate terminal panicles, also from distal axils, green, leafless at least distally. |
terminal, erect, compact, pyramidal panicles and also some axillary clusters, green or silvery green, occasionally tinged with red, leafless at least distally. |
Staminate flowers | inconspicuous, mostly at tips of inflorescences; tepals 3; stamens 3. |
clustered at tips of inflorescences; tepals 2–3; stamens 2–3. |
Pistillate flowers | tepals 3, narrowly elliptic, obovate-elliptic or spatulate, not clawed, ± equal, 1.2–1.7 mm, apex rounded or nearly acute, mucronate or not; style branches erect; stigmas 3. |
tepals 2–3, narrowly elliptic or oblanceolate, not clawed, equal or subequal, 1.2–2 mm, apex broadly acute; style branches erect; stigmas 3. |
Seeds | black or dark brown, subglobose to thick-lenticular, 1 mm diam., minutely punctulate, rather dull. |
very dark brown to black, 1–1.2 mm diam., shiny, filling only proximal portion of fruit. |
Utricles | ovoid to compressed-ovoid, 1–1.6 mm, equaling or slightly exceeding tepals, prominently or faintly rugose, indehiscent. |
marked with 2(–3) green lines that intersect at apex and divide fruit into halves or quarters, slightly to distinctly inflated, ellipsoid, 2–3 mm, distinctly longer than tepals, smooth (in dry plants wrinkled or rugose), indehiscent. |
Amaranthus viridis |
Amaranthus deflexus |
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Phenology | Flowering summer–fall. | Flowering summer–fall. |
Habitat | Fields, railroads, lawns, gardens, waste areas, other disturbed habitats | Weedy areas, ballast heaps, railroads, other disturbed habitats |
Elevation | 0-1000 m (0-3300 ft) | 0-500 m (0-1600 ft) |
Distribution |
AL; AR; AZ; FL; GA; LA; MA; MI; MS; NC; NM; NY; OK; PA; SC; TN; TX; VA; native to South America [Introduced in North America; introduced in tropical and subtropical regions worldwide]
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AL; CA; FL; GA; LA; MA; NJ; NY; OR; PA; TN; VA; native to South America [Introduced in North America; locally introduced or naturalized in tropical to warm-temperate regions of the globe]
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Discussion | The hybrid between Amaranthus deflexus and A. muricatus was described from Europe as A. ×tarraconensis Sennen & Pau (see J. L. Carretero 1979) and may be expected in North America in the future in places of possible co-occurrence of the parental species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 4, p. 429. | FNA vol. 4, p. 430. |
Parent taxa | Amaranthaceae > Amaranthus > subg. Albersia | Amaranthaceae > Amaranthus > subg. Albersia |
Sibling taxa | ||
Synonyms | A. gracilis | |
Name authority | Linnaeus: Sp. Pl. ed. 2, 2: 1405. (1763) | Linnaeus: Mant. Pl. 2: 295. (1771) |
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