Smooth Joyweed

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.

On sandy clay or sandy loam, habitat not noted in Pakistan; elsewhere usually on flat, rather bare ground, not infrequently where subject to periodi¬cal inundation.

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. Inflores-cences 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.

Herbs perennial. Stem densely barbellate hairy, glabrescent. Leaf blade oblanceolate or spatulate, 1.5-2 × 0.3-0.5 cm, abaxially barbellate hairy, apex obtuse to rounded. Heads sessile, ovoid to globose, often hairy at base. Tepals white, ovate-oblong, scarious, hairy along veins, outer 3 segments: 3-veined in proximal half, inner 2 somewhat laterally compressed, 1-veined, apex acute to mucronate. Stamens 5; anthers yellow, ellipsoid; staminodes 3- or 4-toothed, ca. 1/2 as long as stamens; stigma capitate. Utricle brown, obcordate.

Perennial herb with a stout vertical rootstock, mat-forming with numerous prostrate branches which root at the nodes, mats to c. 80 cm across. Branches ± white-villous when young (especially at the upper nodes), finally glabrescent and yellowish or reddish, striate. Leaves moderately white-villous when young but finally glabrescent on the upper surface and thinly hairy below, 8-43 x 2-12 mm, the elliptic, oval or obovate lamina obtuse or subacute at the apex, narrowed below into a long, indistinctly demarcated petiole which in the larger leaves almost equals the lamina in length. Inflorescences sessile, axillary, solitary or 2-3 together, ± globose or finally ovoid, 4-8 mm in diameter; bracts firm, membranous, white, ovate-acuminate, mucronate with the ex-current midrib, c. 2.75 mm, bracteoles similar but smaller and slightly narrower, c. 2.5 mm, falling with the fruit. Tepals white, subequal, oblong-lanceolate, acute, the outer two 3-4.5 mm, the inner three 2.5-4 mm, all prominently 3-nerved to about the middle and darker in the nerved area, mucronate with the excurrent midrib, ± pilose in the lower half with patent, white, minutely barbellate hairs. Stamens 5, all fertile, at anthesis slightly exceeding the ovary and style, the alternating pseudostaminodes much shorter than the filaments, oblong, dentate about the apex. Ovary compressed, narrowed below; style very short, broader than long. Fruit compressed, narrowed below; style very short, broader than long. Fruit compressed, orbicular-obcordate, c. 1.75-2 mm, seed discoid, c. 1.25 mm, brownish, shining, faintly reticulate.

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.

C-E Nepal: Native to tropical America, naturalised in many other tropical areas.

Distribution: A native of tropical America from Mexico and the West Indies south to Brazil, becoming widespread as an introduced weed in India, Java and other parts of the Old World tropics.

100-2200 m

Flowering spring-late fall, year-round in far south.

Ballast ground, swamps, sandy places, limestone near salt water; 0-10m.

Herbs

Guangdong, Hainan, Taiwan [native to tropical America].

Illecebrum ficoideum Jacquin, Select. Stirp. Amer. Hist., 88. 1763, not Linnaeus 1762