Froelichia floridana |
Amaranthaceae |
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field snakecotton, Florida Snake-cotton, plains Snake-cotton |
amaranth family |
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Habit | Plants annual; taproots semi-woody. | Herbs, rarely subshrubs, annual or perennial; trichomes simple (branched in Tidestromia). | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Stems | 1, erect or ascending, sometimes procumbent, simple or sparsely branched (rarely much-branched) from base or above, stout, to 18 dm, puberulent or tomentulose with short, viscid, whitish or brownish hairs. |
without nodal spines (Amaranthus spinosus sometimes with paired nodal spines). |
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Leaves | principally on proximal 1/3 of plant, petiolate; blade lanceolate to oblanceolate, oblong, or linear, largest leaves 3.8–11.2(–21) × 0.5–3.8(–4.2) cm, base attenuate to cuneate, apex acute to obtuse, canescent to subscabrous adaxially, sericeous-tomentose abaxially. |
alternate or opposite, exstipulate, usually petiolate; blade margins entire (entire or serrulate in Iresine; entire, crispate, or erose in Amaranthus). |
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Inflorescences | cymules arranged in spikes, panicles, thyrses, heads, glomerules, clusters, or racemes; each flower subtended by 1 bract and 2 bracteoles (latter sometimes 1 or absent in Amaranthus). |
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Spikes | dense, much-branched, apex often pyramidal, flowers arranged in 5-ranked spiral; bracteoles stramineous or blackish, pubescent with small tufts distally. |
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Flowers | 4–6 mm; perianth lobes, greenish white to pinkish, oblong, apex acute; filament lobes slightly to greatly recurved distally, stramineous to pinkish, apex acute. |
bisexual or unisexual (plants then monoecious or dioecious), hypogynous, generally small or minute; tepals mostly (1–)4–5 or absent, distinct or connate into cups or tubes, scarious, chartaceous, membranaceous, or indurate; stamens 2–5, filaments basally connate into cups or tubes, rarely distinct, alternating with pseudostaminodes (appendages on staminal tubes) or not, anthers 2-locular with 1 line of dehiscence or 4-locular with 2 lines of dehiscence; ovary superior, 1-locular; ovules 1 or, rarely, 2–many; style 1 or absent; stigmas 1–3(–5). |
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Fruits | utricles, dry, dehiscent or not. |
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Seeds | black, reddish brown, or brown, lenticular, subglobose or globose (rarely cylindric), usually small; embryo peripheral, surrounding mealy perisperm. |
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Utricles | flask-shaped, 5 × 4–5 mm, with irregularly dentate lateral wings, both surfaces of perianth with distinct spines or tubercles. |
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2n | = 58 + 2. |
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Froelichia floridana |
Amaranthaceae |
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Phenology | Flowering summer. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Habitat | Open sand prairies, edges of woodlands in sandy soils, roadsides, railroad rights-of-way | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Distribution |
AL; AR; CO; FL; GA; IA; IL; IN; KS; KY; LA; MD; MI; MN; MS; NC; ND; NE; OH; OK; SC; SD; TX; WI; West Indies [Introduced in Australia]
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Nearly worldwide; most abundant in tropics; subtropics; and warm-temperate regions; evidently absent from alpine and arctic regions |
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Discussion | Froelichia floridana ranges from broad-leaved stout herbs surpassing 1 meter in height to much-branched plants forming bushes to 2 meters in diameter and single-stemmed, erect herbs 1 dm in height. Much of the variation in the species has been difficult to ascribe to either geographic or ecologic differences and reflects inherent genetic variability and wide environmentally induced plasticity. Although specialists and taxonomists have implied the existence of well-delineated morphologic taxa with a strong geographic correspondence, this is not always true, and, in fact, one encounters typical specimens of any given variety sporadically throughout the range of the species. Some variability in Froelichia floridana is clearly attributable to geography, principally in terms of general morphologic trends. There is a cline toward long, narrow, almost linear leaves as one moves east along the Gulf Coast and into Florida. This would culminate in the little-known var. pallescens Moquin-Tandon, a linear-leaved form (leaf length more than eight times width) from peninsular Florida. Additional variation ascribable to geography is observed in plants traditionally included in F. drummondii, these being large, stout plants with broader leaves, more obtuse leaf apices, and more densely fulvous pubescence on the abaxial surfaces of leaves. Plants of this form are generally restricted south of the Brazos River and continue to the southern extent of the range in Kenedy County, Texas. Further work examining this variation using micromorphology or molecular markers may elucidate a reliable means to identify intraspecific taxa within F. floridana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera ca. 65, species ca. 900 (12 genera, 80 species in the flora). Centers of diversity for Amaranthaceae are southwestern North America, Central America, South America, and Africa south of the Sahara Desert. Generic limits are not well defined in some groups; fewer than 60 or more than 70 genera could be recognized. Some species occur in severe habitats such as sandy, calcareous, gypseous, saline, or serpentine soils in deserts, semideserts, and seashores. Some species are weedy, including the major agricultural weeds in Amaranthus. Some species are cultivated as ornamentals, particularly Amaranthus caudatus (love-lies-bleeding), A. hypochondriacus (prince’s-feather), A. tricolor (Joseph’s-coat), Celosia cristata (cockscomb), and Gomphrena globosa (globe-amaranth). Native Americans domesticated white-seeded grain amaranths (A. caudatus, A. cruentus, and A. hypochondriacus) for use as cereal grains. Some species of Amaranthus and Celosia are potherbs. Amaranthaceae are usually divided into subfamilies Amaranthoideae (anthers 4-locular with two lines of dehiscence) and Gomphrenoideae Schinz (anthers 2-locular with one line of dehiscence). Amaranthaceae and Chenopodiaceae have long been recognized as allied families that share a number of features: generally small flowers, one perianth whorl, a syncarpous gynoecium with a superior ovary and often only one ovule, basal or free-central placentation, pollen characteristics, centrospermous embryo development, betalain pigments, and P-type form (c) sieve-element plastids. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 4, p. 446. | FNA vol. 4, p. 405. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | Amaranthaceae > Froelichia | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Synonyms | Oplotheca floridana, F. campestris, F. floridana var. campestris, F. floridana var. pallescens | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | (Nuttall) Moquin-Tandon: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 13(2): 420. (1849) | Jussieu | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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