Jepson eFlora
Key to families | Table of families and genera

Key to Polygonaceae

View taxon page for Polygonaceae

1. Ocreae present, persistent or not; nodes generally swollen; flower cluster not subtended by involucre; pedicels all subtended by 2+ fused, membranous, wide bractlets (Polygonoideae)

2. Perianth parts (5)6 (Rumiceae)

3. Flowers unisexual, outer perianth parts of pistillate flower spine-tipped in fruit ..... EMEX

3' Flowers generally bisexual, outer perianth parts not spine-tipped in fruit ..... RUMEX

2' Perianth parts 4–5

4. Perianth parts 4; fruit elliptic, 2-winged; leaves ± basal ..... OXYRIA

4' Perianth parts 4–5; fruit generally ovoid; leaves generally cauline

5. Vine-like shrub; perianth in fruit fleshy (Coccolobeae) ..... MUEHLENBECKIA

5' Herb, or if shrub then not vine-like; perianth in fruit generally not fleshy (Polygoneae)

6. Outer perianth parts winged or keeled, or ± so

7. Flower base stalk-like; outer perianth parts winged (keeled in Fallopia convolvulus); leaf blade base sagittate, hastate, cordate, truncate, or ovate; ocrea papery, not 2-lobed distally ..... FALLOPIA

7' Flower base not stalk-like; outer perianth parts keeled; leaf blade base tapered (ovate); ocrea generally translucent, 2-lobed distally ..... POLYGONUM (2)

6' Outer perianth parts not winged or keeled

8. Leaves generally basal; inflorescence terminal, spike-like; stems not branched ..... BISTORTA

8' Leaves cauline; inflorescence terminal, axillary, spike-like or not; stems generally branched

9. Ocreae generally translucent, glabrous, 2-lobed, fibrous in age ..... POLYGONUM (2)

9' Ocreae opaque, glabrous to scabrous, not 2-lobed

10. Inflorescence raceme- or panicle-like; perianth parts fused ± 1/4; stamens 8 ..... ACONOGONON

10' Inflorescence ± head-, spike-, or panicle-like; perianth parts fused 1/4–2/3; stamens 5–8 ..... PERSICARIA

1' Ocreae 0; nodes not swollen; flower clusters subtended by involucre of 1+ free or fused bracts (or not, in Gilmania); pedicels each often subtended by 2 free, transparent, linear bractlets (Eriogoneae-Eriogonoideae)

11. Involucre bract 1, inflated, awns 0; leaves generally lobed; stamens 6 (Pterostegiinae) ..... PTEROSTEGIA

11' Involucre 0 or tubular or of 2–5 ± free bracts, not inflated, awned or not; leaves entire; stamens 3–9 (Eriogoninae)

12. Annual to shrub, if annual then involucre tubular, awnless

13. Involucres of 2–5 awnless bracts ..... DEDECKERA

13' Involucres tubular ..... ERIOGONUM

12' Annual; involucres tubular and awned or of free or basally fused bracts, awned or not, 0 in Gilmania

14. Leaves basal and cauline, opposite ..... GOODMANIA

14' Leaves basal or if cauline then alternate or whorled

15. Involucre 0 ..... GILMANIA

15' Involucre present

16. Involucres of free or basally fused bracts

17. Stamens 3

18. Perianth lobes leathery; involucre bracts 3, awned ..... LASTARRIAEA

18' Perianth lobes petal-like; involucre bracts many, awnless ..... NEMACAULIS

17' Stamens 6 or 9

19. Involucre bracts 3(4), awned; plant tomentose ..... HOLLISTERIA

19' Involucre bracts 4–7, awnless; plant silky-puberulent ..... JOHANNESHOWELLIA

16' Involucres tubular

20. Involucre funnel- to bell-shaped, not angled, not ridged

21. Involucre awns 5(6); perianth lobes 3-lobed to fringed ..... SIDOTHECA

21' Involucre awns (3)4(5) or 7–36; perianth lobes generally entire

22. Involucre awns 4(5) or generally 7–30(36) ..... ACANTHOSCYPHUS

22' Involucre awns (3)4 ..... OXYTHECA

20' Involucre generally ± cylindric, angled or not, ridged or not

23. Bracts generally 2, opposite, or many, whorled; flowers 1(2) ..... CHORIZANTHE

23' Bracts 3, alternate, on 1 side of branch or not; flowers (1)2–6

24. Involucre teeth 5, awns at tips; flowers 4(6) ..... ARISTOCAPSA

24' Involucre teeth 2–4 or 6, if 5 then awns both at base of involucre and at tips of teeth; flowers (1)2–3

25. Involucre not awned basally

26. Flower hairy; bracts below involucre obvious; involucre teeth unequal ..... MUCRONEA

26' Flower glabrous, bumpy; bracts below involucre obscure; involucre teeth equal ..... SYSTENOTHECA

25' Involucre awned basally

27. Involucre 3-angled, basal awns 3, terminal (on teeth) 5; flowers 2 ..... CENTROSTEGIA

27' Involucre 6-angled, basal awns 6, terminal (on teeth) 6; flowers 3 ..... DODECAHEMA


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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