Polygonum
Creators: name: Keskin, Mustafa
name: Severoğlu, Zeki
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Polygonaceae
Polygonum

description: A diagnostic key to of the Polygonum species occurring in Turkey follow.
1. Annuals with slender root system.......................................................................................................................................................2
- Perennials with thick and woody root system ..................................................................................................................................17
2. Achenes longer than tepals; shore plants.................................................................................................................... P. mesembricum
- Achenes at most slightly longer than tepals; usually land plants .......................................................................................................3
3. Tepals 3–4 mm long; leaves 12–45 mm long, quickly deciduous...................................................................................... P. bellardii
- Tepals usually shorter than 2.5 mm long; leaves average 5–25 mm long not quickly deciduous......................................................4
4. Ochrea without veins..........................................................................................................................................................................5
- Ochrea veined.....................................................................................................................................................................................6
5. Leaves revolute, obovate; plants usually erect......................................................................................................... P. cappodocicum
- Leaves flat, linear to lanceolate; plants prostrate ..................................................................................................... P. polycnemoides
6. Tepal pouched at base....................................................................................................................................................... P. buxiforme
- Tepal smooth, not pouched.................................................................................................................................................................7
7. Inflorescence short and congested, spike like; mostly growing in dunes or fine-grained soil........................................ P. arenarium
- Inflorescence long and loosely arranged; mostly growing in land.....................................................................................................8
8. Most of middle leaves up to 2 mm wide ............................................................................................................................................9
- Most middle leaves wider than 2 mm ...............................................................................................................................................14
9. Internodes very short and covered by leaf and ochrea; achenes usually black ......................................................... P. rottboellioides
- Internodes not covered by leaf and ochrea; achenes brown to dark brown......................................................................................10
10. Flowers solitary in axils of scarious bracts; leaves subulate to filiform, 0.5 mm wide................................................ P. salsugineum
- Flowers 1–3 in axils of leaflike bracts; leaves 0.8–2.2 mm wide.....................................................................................................11
11. Short and sterile shoots present; the edges of the leaves here are folded longitudinally; fruiting tepals suburceolate to urceolate.... ............................................................................................................................................................................................ P. urnigera
- Sterile shoots absent; leaves flat or rarely somewhat folded; fruiting tepals at most suburceolate (some perennials e.g. P. karacae) but usually adjacent at the tip or open..............................................................................................................................................12
12. Longest pedicel 2.0– 2.5 mm, longer than tepals ............................................................................................................ P. pulchellum
- Longest pedicel usually shorter than 2 mm, shorter than tepals.......................................................................................................13
13. Tepal tube about as long as the lobes; ochrea 3–8 mm long ......................................................................................... P. arenastrum
- Tepal tube much shorter than the lobes; ochrea 6–12 mm long ...................................................................................... P. rurivagum
14. Inflorescence usually 4–6 flowered; veins usually not branched on tepals at fruiting time.............................................................15
- Inflorescence usually 1–3 flowered; veins branched on tepals at fruiting time ...............................................................................16
15. Leaves fresh green; ochrea 8–10 mm; pedicels 1.5–3.0 mm; achenes tuberculate........................................................... P. aviculare
- Leaves bluish-green; ochrea 4–8 mm; pedicels 1–2 mm; achenes smooth................................................................ P. argyrocoleon
16. Leaves 25–40 mm; ochrea 7–9 mm; achenes 2–2.5 mm ..................................................................................................... P. patulum
- Leaves 4–35 mm; ochrea 4–8 mm; achenes 1.2–1.8 mm ................................................................................................ P. neglectum
17. Shore plants; ochrea longer than nodes .......................................................................................................................... P. maritimum
- Land plants; ochrea usually shorter than nodes.................................................................……….……………….……….……... 18
18. Ochrea 3–nerved, entirely membranous and equal or longer than internodes ................................................................. P. cognatum
- Ochrea (5–)10–nerved, tube brownish, shorter than internodes.......................................................................................................19
19. Leaf-like bracts absent towards the top............................................................................................................................... P. karacae
- Bracts similar to leaves but shorter ..................................................................................................................................................20
20. Ochrea and leaves overlapping; the plant looks whitish due to hyaline ochrea; leaves mucronate; tepals 1–1.5 mm long ................ ................................................................................................................................................................................. P. paronychioides
- Not as above .....................................................................................................................................................................................21
21. Leaves quickly deciduous at flowering time; plant prostrate with some shoots erect ............................................... P. e quisetiforme
- Leaves not deciduous at flowering time; plants usually strict..........................................................................................................22
22. Prostrate or stoloniferous plants with 40–150 cm tall; inflorescence present on short and third shoots ........................... P. longipes
- Plants suffrutescent with hard woody stocks; inflorescence usually on main shoots ......................................................................23
23. Tepals shorter than 2.5 mm long ......................................................................................................................................................24
- Tepals longer than 2.5 mm long .......................................................................................................................................................27
24. Stem and leaves ashy–glaucous; tepal with sparse pink glands near the base ............................................................. P. praelongum
- Stem and leaves green; tepal unglandular ........................................................................................................................................25
25. Inflorescence a lax, elongated spike; leaves overlapping at the base; tepals 1.7–2.0 mm long.................................... P. s alebrosum
- Inflorescences densed, like a head or congested spike; leaves loosely not overlapping; tepal 2.0– 2.5 mm long............................26
26. Stem 15–70 cm; 2–4 flowers in fascicle; pedicels 1–3 mm ................................................................................................ P. melihae
- Stem 21–32 cm; 5–7 flowers in fascicle; pedicels 3–5 mm ............................................................................................ P. afyonicum
27. Leaves pustulate; achenes longer than tepals .............................................................................................................. P. istanbulicum
- Leaves smooth; achenes shorter or at most equal to tepals ..............................................................................................................28
28. Flowers sessile or rarely with at most 1.5 mm pedicel..................................................................................................... P. sivasicum
- Flowers obviously pedicellate ..........................................................................................................................................................29
29. Leaves usually 10 mm wide and strongly revolute at the margin .................................................................................... P. luzuloides
- Leaves 4–5 mm wide on average and flat or slightly revolute margin.............................................................................................30
30. Ochrea not veined; tepals 3.5–4.5 mm long; achenes equal to slightly longer than tepals ............................................ P. ekimianum
- Ochrea strongly veined; tepals 2.5–3.5 mm long; achenes slightly shorter than tepals...................................................................31
31. Leaves usually undulate margin; achenes brown ......................................................................................................... P. samsunicum
- Leaves flat margin; achenes blackish .................................................................................................................................. P. setosum
description: Published as part of Keskin, Mustafa & Severoğlu, Zeki, 2022, Novelties in the genus Polygonum (Polygonaceae) in Turkey, pp. 113-123 in Phytotaxa 538 (2) on pages 120-121, DOI: 10.11646/phytotaxa.538.2.3, http://zenodo.org/record/6333680