Alternanthera pungens
| Family: | Amaranthaceae |
| Full name: | Alternanthera pungens Kunth |
| Location: | Kyffhäuser (2416AD + 2416CB) |
| ID status: | Fairly certain |
| Afrikaans common name(s): | Kakiedubbeltjie |
| English common name(s): | Khaki weed, Khakiweed, Paper thorns |
| Synonym(s): | Achyranthes repens L. Alternanthera achyrantha (L.) Sweet Alternanthera achyrantha R.Br. Alternanthera echinata Sm. Alternanthera repens (L.) Link - non J.F.Gmel. Illecebrum achyrantha L. Illecebrum obliquum Schumach. fide Fl. Trop. Africa 6(1): 74 (1909). |
| Status: | Alien |
| Description: | Prostrate, mat-forming herb, growing from a tap root. Stems rooting at the nodes. Inflorescences somewhat spiny, due to long bracteoles and awns on the tepals. (from Flora of Zimbabwe website) Prostrate perennial with a stout, vertical rootstock, also rooting at the lower nodes, much-branched from the base outwards to form mats up to c. 1 m across. Stem and branches at first densely villous with long white hairs, later glabrescent. Leaves broadly rhomboid-ovate to obovate, 1.5–4.5 x 0.3–2.7 cm, rounded or subacute at the apex with the mucro frequently bristle-like when young, attenuate below, glabrous or rather thinly appressed-hairy. Inflorescences sessile, commonly 2–3 together, 0.5–1.5 x 0.5–1 cm, globose to shortly cylindrical. Tepals extremely dissimilar: outer 2 (abaxial) deltoid-lanceolate, c. 5 mm, with a spinous arista; inner (adaxial) oblong, flat, c. 3 mm, strongly dentate at the apex, mucro short and fine; lateral tepals c. 2 mm, sinuate in lateral view with the two sides connivent; all tepals with tufts of glochidiate, barbellate hairs. Stamens 5, all with anthers, pseudostaminodes broad and quadrate or shorter, entire to dentate. Style as wide as or wider than long. Fruit roundish, c. 2 mm, rounded to retuse at the tip. (from JSTOR Global Plants website / Flora Somalia) Prostrate, mat-forming perennial herb with a stout vertical rootstock, also rooting at the lower nodes, much-branched from the base outwards, mats up to c. 1 m across. Stem and branches terete, striate, stout to more slender, more or less densely villous with long, white hairs but frequently glabrescent with age. Leaves broadly rhomboid-ovate to broadly elliptic or obovate, 1.5–4.5 x 0.3–2.7 cm, rounded to subacute at the apex with a mucro which in the young leaves is often fine and bristle-like, narrowed below to a petiole up to 1 cm long, glabrous or thinly appressed-pilose on both surfaces, especially on the lower surface of the primary venation. Inflorescences sessile, axillary, solitary or more commonly 2–3 together, globose to shortly cylindrical, 0.5–1.5 cm long and 0.5–1 cm wide; bracts membranous, white or stramineous, 4–5 mm long, deltoid-ovate, glabrous, marginally ciliate or dorsally pilose, distinctly aristate with the excurrent midrib, more or less denticulate around the upper margin; bracteoles similar but smaller, 3–4 mm long, falling with the fruit. Tepals extremely dissimilar; the 2 outer (abaxial) deltoid-lanceolate, 5 mm long, denticulate above, very rigid, 5-nerved below (the intermediate pair much shorter and finer), outer 2 nerves meeting above to join the pungently excurrent midrib, which forms a long arista c. one third of the length of the entire tepal; inner (adaxial) tepal oblong, flat, 3 mm, blunt and strongly dentate at the apex, 3-nerved below but the nerves meeting well below the apex and the apical mucro short and fine; lateral tepals c. 2 mm long, sinuate in lateral view with the two sides of the lamina connivent and denticulate above, sharply mucronate; abaxial and adaxial petals with small tufts of glochidiate and barbed whitish bristles about the basal angles, the lateral tepals each with a large tuft about the centre of the midrib. Stamens 5, all with anthers, at anthesis subequalling or slightly exceeding the ovary and style, the alternating pseudostaminodes broad, subquadrate or shorter, entire to dentate. Ovary compressed, squat, style very short, as wide as or wider than long. Fruit orbicular, rounded to retuse above, 0.2 mm long. Seed discoid, c. 1.25 mm in diam., brown, shining, faintly reticulate. (from JSTOR Global Plants website / Flora Zambesiaca) |
| Link(s) |
African Plant Database
JSTOR Plant Science Kew Herbarium Catalogue BGBM Berlin-Dahlem - Virtual Herbarium Züricher Herbarien iNaturalist (Namibia / Alex Dreyer) iNaturalist (Namibia) iNaturalist (southern Africa) Flora of Zimbabwe Fleurs de notre Terre - Galerie Namibie Tree Atlas of Namibia |
| Photographer: | AA Dreyer |
| Date of photograph: | 22 Apr 2011 |
| Camera make: | Panasonic |
| Camera model: | DMC-FZ45 |
| Lens aperture: | f/6.3 |
| Shutter speed: | 1/250 s |
| ISO speed: | 80 |
| Content last updated: | 18 Apr 2024 |
