Alternanthera sessilis

(Linnaeus) R. Brown ex de Candolle

Cat. Pl. Hort. Monsp., 77. 1813.

Common names: Sessile joyweed
WeedyIntroducedIllustrated
Basionym: Gomphrena sessilis Linnaeus Sp. Pl. 1: 225. 1753
Treatment appears in FNA Volume 4. Treatment on page 450. Mentioned on page 448, 449.

Herbs, annual or perennial, 2–6 dm. Stems procumbent, pubescent in lines, glabrate. Leaves sessile; blade elliptic to oblong or oblanceolate, 1.2–5 × 0.5–2.2 cm, apex obtuse to acute, glabrous. Inflorescences axillary, sessile; heads white, subglobose or ovoid, 0.5–1.1 cm; bracts keeled, ca. 1/2 as long as tepals. Flowers: tepals white, ovate to lanceolate, 2–3.5 mm, apex acuminate, hairs not barbed; stamens 5; anthers 3–5, globose; pseudostaminodes subulate, margins laciniate. Utricles included within tepals, sides exerted in mature fruit, greenish stramineous, obcordate, 1.3–1.7 mm, apex retuse. Seeds lenticular, 0.9–1.1 mm.


Phenology: Flowering summer–early fall.
Habitat: Wet disturbed areas
Elevation: 0-20 m

Distribution

V4 884-distribution-map.gif

Introduced; Ala., Fla., Ga., La., Mexico, West Indies, Central America (Belize), Central America (Costa Rica), Central America (Guatemala), Central America (Nicaragua), Central America (Panama), South America, Africa, Asia

Discussion

Alternanthera sessilis is reported from Maryland, Mississippi, South Carolina, and Texas, but I have seen no specimens from these states.

Selected References

None.

Lower Taxa

None.
... more about "Alternanthera sessilis"
3 +  and 5 +
Steven E. Clemants +
(Linnaeus) R. Brown ex de Candolle +
Gomphrena sessilis +
1.2 cm12 mm <br />0.012 m <br /> (5 cm50 mm <br />0.05 m <br />) +
elliptic +  and oblong or oblanceolate +
0.5cm;2.2cm +
Sessile joyweed +
Ala. +, Fla. +, Ga. +, La. +, Mexico +, West Indies +, Central America (Belize) +, Central America (Costa Rica) +, Central America (Guatemala) +, Central America (Nicaragua) +, Central America (Panama) +, South America +, Africa +  and Asia +
0-20 m +
peripheral +
hypogynous +
minute +  and small +
not +  and dehiscent +
Wet disturbed areas +
several-flowered +
ovoid +  and subglobose +
0.5 cm5 mm <br />0.005 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
subtending +
laciniate +
Flowering summer–early fall. +
Cat. Pl. Hort. Monsp., +
lenticular +
Weedy +, Introduced +  and Illustrated +
several-flowered +
cylindric +
decumbent +  and prostrate +
erect +  and ascending +
2-lobed +  and capitate +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Alternanthera sessilis +
Alternanthera +
species +
distinct +
ovate +  and lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
indurate +, membranaceous +, chartaceous +  and scarious +
greenish stramineous +
indehiscence +
obcordate +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
perennial +  and annual +