Alternanthera sessilis (L.) DC.

Amaranthaceae, C. C. Townsend. Flora Zambesiaca 9:1. 1988

Morphology General Habit

Annual or usually perennial herb; in drier situations with slender, more solid stems, prostrate, decumbent or erect, more or less much-branched, to c. 30 cm.; in wetter places ascending or most commonly prostrate with stems c. 0.1–1 m. long, rooting at the nodes, more or less fistular, with numerous lateral branches; when floating very fistular, the stems attaining a metre or more in length and over 1 mm. thick, with long clusters of whitish rootlets at the nodes.

Morphology Stem

Stem and branches green to pink or purplish, with a narrow line of whitish hairs down each side of the stem and branches (at least when young) and tufts of white hairs in the branch and leaf axils, otherwise glabrous, striate, terete below, more or less tetragonous above.

Morphology Leaves

Leaves extremely variable in shape and size, linear-lanceolate to oblong, oval, or obovate-spathulate, 1–9 (15) × 0.2–2(3) cm., blunt to shortly acuminate at the apex, cuneate to attenuate at the base, glabrous or thinly pilose, especially on the inferior surface of the midrib; petiole obsolete to c. 5 mm. long.

Morphology Reproductive morphology Inflorescences

Inflorescences sessile, axillary, solitary or in clusters of up to c. 5, subglobose (slightly elongate in fruit), c. 5 mm. in diam.; bracts scarious, white, deltoid-ovate, mucronate with the excurrent pale midrib, glabrous, c. 0.75–1 mm. long; bracteoles similar, 1–1.5 mm., also persistent.

Morphology Reproductive morphology Flowers Tepal

Tepals oval-elliptic to lanceolate-ovate, equal, 1.5–2.5 mm. long, acuminate to rather blunt, white to pink-tinged, glabrous, shortly but distinctly mucronate with the stout, excurrent midrib, the margins often obscurely lacerate-denticulate.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 5 (2 filaments anantherous), at anthesis subequalling the ovary and style, the alternating pseudostaminodes resembling the filaments but usually somewhat shorter.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary strongly compressed, roundish, style extremely short.

Morphology Reproductive morphology Fruits

Fruit glabrous, obcordate or cordate-orbicular, 2–2.5 mm. long, dark at maturity, strongly compressed with the margins each side of the seed not much thicker than the narrow, pale, yellowish keel, slightly longer to slightly shorter than the perianth.

Morphology Reproductive morphology Seeds

Seed discoid, c. 0.75–1 mm. in diam., brown, shining, faintly reticulate.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/164480/120120173

Conservation

LC - least concern

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Trailing or scandent herb of open places or shallow water; stems ribbed with lines of pubescence between ribs; horizontal rows of longer trichomes at nodes

Morphology Leaves

Leaves with indistinct petioles; blades ovate to elliptic, to 5 cm long, sparsely pubescent below, apex acute to obtuse, base tapering

Morphology Reproductive morphology Inflorescences

Inflorescences congested, axillary, bracts often persistent after flowers have fallen; bracts and bracteoles ovate 0.3–0.8 mm long, mucronate, hyaline, 1-nerved, apiculate, white, glabrous; anthers 3, ovate; pseudostaminodia subulate or dentate, equal to or shorter than filaments; style <0.2 mm long; stigma punctate

Morphology Reproductive morphology Fruits

Utricles compressed, obcordate, at maturity exceeding tepals; seed lenticular, ca. 1.2 mm in diameter, red-brown.

Distribution

Grand Cayman. Pantropical.

Bernal, R., G. Galeano, A. Rodríguez, H. Sarmiento y M. Gutiérrez. 2017. Nombres Comunes de las Plantas de Colombia. http://www.biovirtual.unal.edu.co/nombrescomunes/

Vernacular

abrojo, alpargatera, amaranto, botoncillo, descancé, escansel, iscansé, moradilla, pampera, pimpollo

Amaranthaceae, C.C. Townsend. Flora of Tropical East Africa. 1985

Morphology General Habit

Annual or usually perennial herb; in drier situations with slender more solid stems, prostrate, decumbent or erect, ± much branched, to ± 30 cm.; in wetter places ascending or most commonly prostrate with stems ± 0.1–1 m. long, rooting at the nodes, ± fistular, with numerous lateral branches; when floating very fistular, the stems attaining a metre or more in length and over 1 cm. thick, with long clusters of whitish rootlets at the nodes.

Morphology Stem

Stem and branches green to pink or purplish, with a narrow line of whitish hairs down each side of the stem and branches (at least when young) and tufts of white hairs in the branch and leaf axils, otherwise glabrous, striate, terete below, ± tetragonous above.

Morphology Leaves

Leaves extremely variable in shape and size, linear-lanceolate to oblong, oval or obovate-spathulate, 1–9(–15) × 0.2–2 (–3) cm., blunt to shortly acuminate at the apex, cuneate to attenuate at the base, glabrous or thinly pilose, especially on the lower surface of the midrib; petiole obsolete to ± 5 mm.

Morphology Reproductive morphology Inflorescences

Inflorescences sessile, axillary, solitary or in clusters of up to ± 5, subglobose (slightly elongate in fruit), ± 5 mm. in diameter; bracts scarious, white, deltoid-ovate, ± 0.75–1 mm., mucronate with the excurrent pale midrib, glabrous; bracteoles similar, 1–1.5 mm., also persistent.

Morphology Reproductive morphology Flowers Tepal

Tepals oval-elliptic to lanceolate-ovate, equal, 1.5–2.5 mm., acuminate to rather blunt, white to pink-tinged, glabrous, shortly but distinctly mucronate with the stout excurrent midrib, the margins often obscurely lacerate-denticulate.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 5 (2 filaments anantherous), at anthesis subequalling the ovary and style, the alternating pseudostaminodes resembling the filaments but usually somewhat shorter.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary strongly compressed, roundish, style extremely short.

Morphology Reproductive morphology Fruits

Fruit glabrous, obcordate or cordate-orbicular, 2–2.5 mm. long, subequalling or slightly shorter than the perianth, strongly compressed, dark brownish with a narrow, pale yellowish, somewhat thickened margin.

Morphology Reproductive morphology Seeds

Seed discoid, ± 0.75–1 mm., brown, shining, faintly reticulate.

Figures

Fig. 29/11–14.

Habitat

Most commonly by or in water, also in damp forests and abandoned cultivation, on many kinds of soil from poor sandy to loam or black cotton; 0–1840 m.

Distribution

very widespread in the tropics and subtropics of both Old and New Worlds K1 K2 K3 K4 K6 K7 P T1 T2 T3 T4 T5 T6 T7

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Naturalizada en Colombia; Alt. 0 - 2000 m.; Andes, Llanura del Caribe, Orinoquia, Pacífico, Valle del Cauca, Valle del Magdalena.

Morphology General Habit

Hierba

Conservation

No Evaluada

Distribution

Biogeografic region: Andean, Caribbean, Orinoquia, Pacific. Elevation range: 0–2000 m a.s.l. Native to Colombia. Colombian departments: Antioquia, Bolívar, Cauca, Chocó, Córdoba, Cundinamarca, Huila, Magdalena, Meta, Nariño, Quindío, Tolima, Valle del Cauca.

Habit

Herb.

Conservation

IUCN Red List Assessment (2021): LC.

Ecology

Habitat according IUCN Habitats Classification: forest and woodland, savanna, shrubland, wetlands (inland), artificial - terrestrial.