Amaranthus muricatus |
Amaranthus obcordatus |
|
---|---|---|
African amaranth, muricate amaranth |
trans-Pecos amaranth |
|
Habit | Plants annual or short-lived perennial, glabrous or slightly pubescent near tips. | Plants glabrous. |
Stems | ascending or prostrate, much-branched from stout rootstock, 0.1–0.4 m. |
erect or ascending, branched, 0.1–0.5 m. |
Leaves | petiole to 1/2 as long as blade; blade linear to narrowly lanceolate, 1.5–8 × 0.2–0.5(–1) mm, base tapering, margins entire, plane to undulate, apex obtuse and often emarginate. |
petiole 1/2 as long as blade; blade oblong-lanceolate to lanceolate-linear, 1–3 × 0.2–1 cm, base cuneate to narrowly cuneate, margins entire, plane or sometimes undulate, apex rounded or obtuse-truncate, mucronate. |
Bracts | of pistillate flowers linear, 0.7–1.2 mm, 1/2–2/3 as long as tepals. |
broadly ovate, 1 mm or shorter, 1/2 or less length of tepals, apex acute. |
Inflorescences | terminal, compact pyramidal panicles and axillary glomerules, erect or reflexed, green, leafless at least distally. |
mostly axillary, but at apex flowers also condensed in terminal spikes or spicate panicles, usually leafy proximally or nearly leafless distally. |
Staminate flowers | intermixed with pistillate or at tips of inflorescences; tepals 5; stamens 5. |
tepals (3–)5; stamens 3. |
Pistillate flowers | tepals 5, narrowly oblanceolate, not clawed, equal, 1.5–2 mm, apex obtuse or subacute; style branches erect; stigmas 3. |
tepals 5, spreading at maturity, spatulate, clawed, subequal, 2 mm, margins fimbriate, apex rounded or shallowly emarginate; stigmas 3. |
Seeds | black, lenticular, 1–1.2 mm diam., semiglossy. |
dark reddish brown to nearly black, lenticular or broadly lenticular, 0.6–0.8 mm diam., smooth. |
Utricles | compressed, subglobose, 1.7–2 mm, ± equaling or slightly exceeding tepals, muricate, indehiscent. |
narrowly oblong, 1–1.4 mm, shorter than tepals, indehiscent. |
Amaranthus muricatus |
Amaranthus obcordatus |
|
Phenology | Flowering summer–fall. | Flowering summer–fall. |
Habitat | Waste places, on ballast | Semideserts, naturally disturbed habitats |
Elevation | 0 m (0 ft) | 1000-1200 m (3300-3900 ft) |
Distribution |
AL; s South America (Argentina, Paraguay, Uruguay) [Introduced in North America; introduced in s Europe, s Africa, Australia, and other regions] |
AZ; TX; n Mexico (Sinaloa, Sonora) |
Discussion | The vernacular name “African amaranth” is sometimes used for this species; it is a misnomer; the species is native to South America and naturalized in Africa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Amaranthus obcordatus has been reported only from southern Arizona (T. H. Kearney and R. H. Peebles 1960), trans-Pecos Texas in Brewster and Pecos counties, and adjacent regions of Mexico (C. F. Reed 1969b). It was also tentatively reported for New Mexico, but no localities were cited (W. C. Martin and C. R. Hutchins 1980). The proper taxonomic position of A. obcordatus and its relationships to other species remain problematic and are in need of further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 431. | FNA vol. 4, p. 427. |
Parent taxa | Amaranthaceae > Amaranthus > subg. Albersia | Amaranthaceae > Amaranthus > subg. Amaranthus |
Sibling taxa | ||
Synonyms | Euxolus muricatus | Amblogyna urceolata var. obcordata |
Name authority | (Moquin-Tandon) Hieronymus: Pl. Diaph. Fl. Argent., 227. (1882) | (A. Gray) Standley: in N. L. Britton et al., N. Amer. Fl. 21: 107. (1917) |
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