Polygonum L.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Herbs or dwarf shrubs, glabrous or hairy

Morphology Leaves Stipules

Ochreae with or without bristles at the margin

Morphology Reproductive morphology Inflorescences

Flowers bisexual, in spikes (in Somalia), solitary or variously clustered

Morphology Reproductive morphology Flowers Tepal

Tepals 4–5, free or united at the base, petaloid, not enlarging in fruit

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens (5–)8

Morphology Reproductive morphology Flowers Gynoecium Style

Styles 2 or 3; stigmas capitate

Morphology Reproductive morphology Fruits

Nuts trigonous or lens-shaped, enclosed in the persistent perianth or partly exserted.

Distribution

Cosmopolitan genus of some 115 species.

Note

The Somali species belong to sect. Persicaria (Mill.) DC., a group which is often given generic rank (see, e.g., Wilson in Kew Bull. 45: 621–636 (1990).

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

Morphology Leaves

Leaves alternate, small, usually less than 2 cm long and articulated at the base, lanceolate-elliptic to oblong Leaves alternate, small, usually less than 2 cm long and articulated at the base, lanceolate-elliptic to oblong.

Morphology Leaves Ocrea

Ocrea membranaceous, silvery or white, often deeply lacerate, glabrous Ocrea membranaceous, silvery or white, often deeply lacerate, glabrous.

Morphology Reproductive morphology Flowers

Flowers hermaphrodite, rarely unisexual, solitary or in sessile fascicles springing from the axils of bracts; bracteoles 2, fused, thinly membranous and contained within the bracts Flowers hermaphrodite, rarely unisexual, solitary or in sessile fascicles springing from the axils of bracts; bracteoles 2, fused, thinly membranous and contained within the bracts.

Morphology Reproductive morphology Flowers Perianth

Perianth segments (4)5, equal or somewhat unequal in length, spirally arranged, often imbricate, free or united in the lower part, petaloid at least in part, with only one main vein (the vein sometimes branched); outer segments keeled or slightly angular, different from the inner Perianth segments (4)5, equal or somewhat unequal in length, spirally arranged, often imbricate, free or united in the lower part, petaloid at least in part, with only one main vein (the vein sometimes branched); outer segments keeled or slightly angular, different from the inner.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4–6, rarely fewer, included or not; filaments broadly dilated in the lower half, free or sometimes united at the base into a ring; anthers globose or ellipsoid, dorsifixed; interstaminal nectaries lacking Stamens 4–6, rarely fewer, included or not; filaments broadly dilated in the lower half, free or sometimes united at the base into a ring; anthers globose or ellipsoid, dorsifixed; interstaminal nectaries lacking.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary included in the perianth; styles (2)3, free; stigmas capitate

Morphology Reproductive morphology Fruits

Nut trigonous, enclosed in the persistent perianth or protruding from it for less than half its length. Nut trigonous, enclosed in the persistent perianth or protruding from it for less than half its length.

Distribution

A cosmopolitan genus of c. 20 species, most occurring in north temperate regions (knotweeds).

Morphology General Habit

Annual or perennial prostrate or semi-erect herbs (rarely shrubs), glabrous or hairy. Annual or perennial prostrate or semi-erect herbs (rarely shrubs), glabrous or hairy

Morphology Stem

Stems much branched. Stems much branched

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary included in the perianth; styles (2)3, free; stigmas capitate.