Polygonum arenastrum Boreau

Flora Zambesiaca. Vol. 9, Part 3. Polygonaceae-Myriaceae. Pope GV, Polhill RM, Martins ES. 2006.

Type

Type from France.

Morphology General Habit

A glabrous, prostrate or ± decumbent, rarely erect, annual herb, forming dense mats A glabrous, prostrate or ± decumbent, rarely erect, annual herb, forming dense mats.

Morphology Stem

Stems up to 70 cm long, much branched, leafy, becoming somewhat woody at the base Stems up to 70 cm long, much branched, leafy, becoming somewhat woody at the base.

Morphology Leaves

Leaves all similar, subsessile, 5–15 × 2–6 mm, elliptic to elliptic.lanceolate, acute at the apex, attenuate to the base Leaves all similar, subsessile, 5–15 × 2–6 mm, elliptic to elliptic-lanceolate, acute at the apex, attenuate to the base.

Morphology Leaves Ocrea

Ocrea silvery at least in the upper part, 3–5 mm long, ferrugineous below, lacerate Ocrea silvery at least in the upper part, 3–5 mm long, ferrugineous below, lacerate.

Morphology Reproductive morphology Flowers

Flowers shortly pedicellate, in axillary fascicles of 2–4 flowers, surrounded by leafy bracts Flowers shortly pedicellate, in axillary fascicles of 2–4 flowers, surrounded by leafy bracts.

Morphology Reproductive morphology Flowers Perianth

Perianth 1.5–2 × 2.5–3 mm, 5-lobed; lobes greenish with white or pinkish margins, at least twice as long as the perianth tube, flat and slightly imbricate Perianth 1.5–2 × 2.5–3 mm, 5-lobed; lobes greenish with white or pinkish margins, at least twice as long as the perianth tube, flat and slightly imbricate.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 6, as long as the perianth; filaments filiform Stamens 6, as long as the perianth; filaments filiform.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 1–1.5 × 1.5–2 mm; styles 3, free, almost sessile

Ecology

Roadsides; c. 1500 m.

Distribution

Like P. aviculare this is a temperate region species which has become a subcosmopolitan weed. It is polymorphic and partially autogamic. Zimbabwe ZIM E

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary 1–1.5 × 1.5–2 mm; styles 3, free, almost sessile.

Morphology Reproductive morphology Fruits

Nut dull but sometimes shiny on the edges, 2–2.5 mm long, trigonous, rarely lenticular, with 2 broad and convex sides and one narrower concave side, striate-punctate. Nut dull but sometimes shiny on the edges, 2–2.5 mm long, trigonous, rarely lenticular, with 2 broad and convex sides and one narrower concave side, striate-punctate.