Alternanthera paronychioides

A. St.-Hilaire

Voy. Distr. Diam. 2: 439. 1833.

Common names: Smooth joyweed
Introduced
Basionym: Illecebrum ficoideum Jacquin Select. Stirp. Amer. Hist., 88. 1763,
Treatment appears in FNA Volume 4. Treatment on page 450. Mentioned on page 448.

Herbs, perennial, 1–8 dm. Stems prostrate, villous, glabrate. Leaves sessile; blade elliptic, ovate-rhombic, or oval, 0.6–2.5 × 0.3–1.1 cm, apex acute or obtuse, villous, soon glabrate. Inflorescences axillary, sessile; heads white, globose, 0.5–1 cm diam.; bracts less than 1/2 as long as tepals. Flowers: tepals monomorphic, white, lanceolate, 3–5 mm, apex acuminate, without rigid, spinose tips, hairs not barbed; stamens 5; anthers 3–5, globose; pseudostaminodes ligulate, shorter than filaments, margins entire or dentate. Utricles included within tepals, stramineous, orbiculate to rounded-obovate, 2–2.3 mm, apex truncate. Seeds lenticular, 1.2–1.5 mm.


Phenology: Flowering spring–late fall, year-round in far south.
Habitat: Ballast ground, swamps, sandy places, limestone near salt water
Elevation: 0-10 m

Distribution

V4 885-distribution-map.gif

Introduced; Ala., Del., Fla., Ga., La., Miss., N.J., N.C., Pa., S.C., Tenn., Tex., Mexico, West Indies, Central America, South America, Asia, Africa, Pacific Islands

Discussion

Plants identified as Alternanthera paronychioides var. amazonica Huber have been collected on salt flats in central Louisiana. The specimens I have seen are not sufficiently distinct to warrant varietal recognition.

Selected References

None.

Lower Taxa

None.
3 +  and 5 +
glabrate +  and villous +
Steven E. Clemants +
A. St.-Hilaire +
Illecebrum ficoideum +
0.6 cm6 mm <br />0.006 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
oval +, ovate-rhombic +  and elliptic +
0.3cm;1.1cm +
0 (?) +  and 1/2 (?) +
Smooth joyweed +
Ala. +, Del. +, Fla. +, Ga. +, La. +, Miss. +, N.J. +, N.C. +, Pa. +, S.C. +, Tenn. +, Tex. +, Mexico +, West Indies +, Central America +, South America +, Asia +, Africa +  and Pacific Islands +
0-10 m +
peripheral +
hypogynous +
minute +  and small +
not +  and dehiscent +
Ballast ground, swamps, sandy places, limestone near salt water +
several-flowered +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
globose +
subtending +
dentate +  and entire +
Flowering spring–late fall, year-round in far south. +
Voy. Distr. Diam. +
lenticular +
Introduced +
several-flowered +
cylindric +
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 paronychioides +
Alternanthera +
species +
distinct +
lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
indurate +, membranaceous +, chartaceous +  and scarious +
indehiscence +
orbiculate +  and rounded-obovate +
0.2 cm2 mm <br />0.002 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +