Contains 5 accepted taxa overall.
Characteristics
It has been recommended that Polygonella be included within Polygonum, as they share dimorphic tepals with a single main vein, sinuate-margined epidermal tepal cells, irregularly ridged cuticle, and filaments with a dilated base and the outer shorter than the inner ones (Ronse De Craene et al. 2004; Schuster et al. 2011, 2015). Plastid sequences have provided support for uniting Polygonella with Polygonum, although nuclear data (ITS) have so far not resolved the relationships.
Classification
Citation
POLYGONUM Linnaeus, Sp. Pl. 359. 1753.
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TYPE: Polygonum aviculare Linnaeus, typ. cons.
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Polygonum aviculare ssp. aviculare | Knotweed | |||
| Polygonum aviculare ssp. depressum | Dooryard Knotweed | |||
| Polygonum erectum | Erect Knotweed | |||
| Polygonum glaucum | Seabeach Knotweed | |||
| Polygonum ramosissimum |
Identification Key
1. Branches appearing directly from the node, not adnate to the stem
2
1. Branch bases adnate to the stem, appearing to arise above the node (Polygonella)
4
2. Stem mostly erect; flowers mostly in terminal, loose, leafy spiciform inflorescences with the distal flowers subtended by leaves subequal to shorter than the flowers
2. Stem prostrate to erect; flowers axillary, with the distal flowers subtended by leaves much longer than the flowers
3
3. Ocrea not pruinose at the base; tepals appressed in fruit; achene dull, tuberculate
3. Ocrea pruinose at the base; tepals ascending-spreading in fruit; achene shiny, smooth
4. Ocrea ciliate at the apex; leaves linear with an acute to acuminate apex
5
4. Ocrea lacking cilia at the apex; leaves generally linear-spatulate to spatulate with an obtuse to rounded apex
8
5. Leaves narrowly linear, usually <1.3 mm wide; inner tepal margin entire to erose; filaments dimorphic
6
5. Leaves linear, larger ones usually 1-3 mm wide; inner tepal margin fimbriate; filaments monomorphic
7
6. Plant with multiple stems at the base of the plant
6. Plant with one main stem at the base of the plant (Polygonella ciliata)
7. Plant 10-60 cm tall; stem minutely scabrous below the inflorescence; leaves without hyaline margins
7. Plant 35-110 cm tall; stem smooth to sparsely scabrous along the angles below the inflorescence; leaves with hyaline margins (Polygonella robusta)
8. Larger leaf blades (3)8-30 mm wide (Polygonella macrophylla)
8. Larger leaf blades 0.3-6(8) mm wide
9
9. Larger leaf blades 16-40(65) mm long (often nearly leafless or with few at maturity); inflorescence (13)20-40 mm long (Polygonella gracilis)
9. Larger leaf blades 4-16(36) mm long (usually abundantly leafy at maturity); inflorescence 4-20(33) mm long
10
10. Plant prostrate; leaf margin not hyaline; stigma and style 0.5-0.8 mm long (Polygonella myriophylla)
10. Plant erect to decumbent; leaf margin hyaline distally; stigma and style ca. 0.1 mm long
11
11. Larger leaf blades 0.5-1.5(2) mm wide
11. Larger leaf blades (2)3-6 mm wide
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| No synonyms found. | |||