Eriogonum grande var. rub. (dark form) is a mat-forming perennial in the Polygonaceae, notable for its tall, stout flowering stems that rise above a basal rosette of leaves. Flower clusters may be white, pink or red and appear from June to September. Leaves are borne mainly at the base, with wavy margins and reach up to 10 centimetres in length. The plant combines a low vegetative habit with conspicuous, upright inflorescences.

Redflower Buckwheat (Eriogonum grande var. rub. (dark form)) forms a low perennial mat and flowers from June to September.

Eriogonum grande var. rub. (dark form)

Redflower Buckwheat | Eriogonum grande var. rub. (dark form)

Persicaria affinis 'Superba' is a mat-forming perennial in the Polygonaceae that forms dense clumps roughly 25 cm high and 60 cm across. It bears cylindrical spikes of pale pink to rose-red flowers from June to August. Leaves are produced mainly at ground level, creating a close carpet beneath the flowering stems.

Persicaria affinis 'Superba' is a mat-forming perennial that flowers from June to August.

Bistorta is a genus of flowering plants in the family Polygonaceae. As of February 2019 about 40 species are accepted.

Persicaria affinis 'Superba'

Himalayan Bistort | Persicaria affinis 'Superba'

Persicaria amp. 'Blackfield' is a cultivated member of the Persicaria genus in the knotweed family, Polygonaceae. As a Persicaria it produces the genus's characteristic flowering spikes and blooms in the UK from July to September. Plants in this genus are herbaceous, with stems and alternately arranged leaves, and may develop from taproots, fibrous roots, rhizomes or stolons. The inflorescences may be arranged as panicles, spikes or compact heads.

Persicaria amp. 'Blackfield' is a Persicaria cultivar that flowers in the UK from July to September and carries the genus's spiked inflorescences.

Persicaria is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds.

Persicaria amp. 'Blackfield'

Persicaria amp. 'Taurus' is a Persicaria in the knotweed family (Polygonaceae) noted for its summer flowering, which runs from July to September. As a member of the genus Persicaria it is herbaceous and shares the group’s range of root and stem habits, from taproots to rhizomes and stolons. Flowers are carried in spike- or panicle-like inflorescences typical of the genus. Expect a plant whose seasonal bloom period provides a clear summer presence in the border.

Persicaria amp. 'Taurus' is a Persicaria (Polygonaceae) that flowers from July to September.

Persicaria amp. 'Taurus

Knotweed | Persicaria amp. 'Taurus

Persicaria amplex. 'Alba' is a member of the Persicaria genus in the Polygonaceae (knotweed) family, valued for its summer display. As with other Persicaria, plants are herbaceous and may show a range of growth habits within the genus. Expect flowering from July to September.

Persicaria amplex. 'Alba' flowers from July to September and belongs to the Polygonaceae family.

Persicaria amplex. 'Alba'

Knotweed | Persicaria amplex. 'Alba'

Persicaria amplex. 'Blackfield' is a cultivar of Persicaria in the knotweed family Polygonaceae, notable for its summer flowering from July to September. It belongs to a genus of herbaceous plants that can be annual or perennial and shows a variety of stem and root habits. Flowers in Persicaria are carried in spikes, panicles or headlike clusters and may range in colour within the genus. The genus often bears a papery ochrea at the leaf nodes.

Persicaria amplex. 'Blackfield' is a Persicaria (Polygonaceae) cultivar that flowers from July to September and benefits from cutting back after flowering.

Persicaria amplex. 'Blackfield'

Knotweed | Persicaria amplex. 'Blackfield'

Persicaria amplex. 'Taurus' is a cultivated form of Persicaria in the knotweed family Polygonaceae, producing spikelike clusters of small flowers. Members of the genus carry flowers that can range from white and greenish through to pink, red and purple; this cultivar flowers in the UK from July to September. The group shows variable root and stem habits, so check the supplier for precise habit and spread.

Persicaria amplex. 'Taurus' is a Persicaria cultivar that produces spikelike flower clusters in the UK from July to September.

Persicaria amplex. 'Taurus'

Knotweed | Persicaria amplex. 'Taurus'

Persicaria rucinata 'Needham's Form' is a cultivar of Persicaria in the knotweed family Polygonaceae. Persicaria comprises herbaceous species commonly referred to as knotweeds or smartweeds, with diverse stem and leaf forms. This cultivar produces flowers from July to September. Consult the supplier for specific notes on flower and foliage appearance.

Persicaria rucinata 'Needham's Form' is a Persicaria cultivar that flowers from July to September.

Persicaria rucinata 'Needham's Form'

Polygonum affine is a perennial from the Himalayas that can form low mats, clumps or produce taller upright flowering stems. Leaves are deciduous, lance-shaped to heart-shaped and are often marked or take on autumn tints. It flowers July to September. It prefers full sun to partial shade and suits moist soils, including heavy clay, but dislikes drought.

Himalayan bistort (Polygonum affine) is a mat-forming perennial that flowers July to September and suits moist soils, borders and rock gardens.

https://en.wikipedia.org/wiki/Bistorta_affinis

The knotweeds are vigorous, long-flowering plants carrying dense narrow spikes or loose sprays of tiny flowers, usually in pink, crimson or greenish white, above simple lance-shaped or heart-shaped foliage that frequently colours well in autumn. Habit varies enormously, from low creeping mats that make dense weed-suppressing cover to tall, architectural clump-formers. Several are extremely vigorous, and the genus has been extensively reclassified, with many garden plants now placed in Persicaria.

Polygonum affine

Himalayan bistort, fleece flower | Polygonum affine

Polygonum affine 'Superbum' is a perennial knotweed notable for its variable habit, forming mats, clumps or sometimes growing more upright. Leaves are deciduous, simple and range from lance-shaped to heart-shaped, often showing markings or an autumn tint. It flowers from July to September and prefers full sun to partial shade. The plant tolerates almost any soil including heavy clay, favours moist conditions and dislikes drought.

Polygonum affine 'Superbum' (Knotweed) suits moist sites in full sun to partial shade and flowers July to September.

Polygonum affine 'Superbum'

Knotweed | Polygonum affine 'Superbum'

Polygonum albinum is a perennial in the knotweed family that can grow as a mat-forming ground cover, a clump, or as tall upright stems. It has deciduous, simple leaves that range from lance-shaped to heart-shaped and are often marked or take an autumn tint. Flowering occurs from July to September. Plants tolerate a wide range of soils, including heavy clay, and are suited to full sun or partial shade.

Knotweed (Polygonum albinum) is a perennial Polygonaceae species flowering July to September that tolerates full sun to partial shade and most soils.

Polygonum albinum

Knotweed | Polygonum albinum

Polygonum amplexicaule is a perennial in the buckwheat family that tolerates moist, even damp, ground and grows to about 1.2 metres. Forms range from mat-forming or clump-forming to taller, upright plants. Leaves are deciduous, simple and lance- to heart-shaped, often marked or taking on autumn tints. It flowers in the UK from July to September.

Red bistort (Polygonum amplexicaule) thrives in moist soil and flowers from July to September in UK gardens.

https://en.wikipedia.org/wiki/Bistorta_amplexicaulis

Polygonum amplexicaule

Red bistort, mountain fleece | Polygonum amplexicaule

Polygonum amplexicaule 'Arun Gem' is a moisture-preferring perennial knotweed that can form mats, clumps or grow more upright to about 1.2 metres. The leaves are deciduous, lance- to heart-shaped and often show markings or autumn tint. It flowers from July to September, giving a summer display. Plants tolerate a wide range of soils, including heavy clay, but dislike drought.

Polygonum amplexicaule 'Arun Gem' is a 1.2m perennial knotweed that flowers July to September and prefers moist soil in sun or part shade.

Polygonum amplexicaule 'Arun Gem'

Red Bistort | Polygonum amplexicaule 'Arun Gem'

Polygonum amplexicaule 'Atrosanguineum' is a perennial from the buckwheat family that tolerates damp soil and reaches about 1.2 metres. It can grow as a mat, a clump or a taller upright plant and has deciduous, lance- to heart-shaped leaves that often show marking or autumn tints. Flowering occurs from July to September on narrow spikes carried above the foliage. It suits a range of soil types, including heavy clay, and favours moist conditions over drought.

Red Bistort (Polygonum amplexicaule 'Atrosanguineum') is a moisture-loving perennial that flowers from July to September and suits borders and damp areas.

Polygonum amplexicaule 'Atrosanguineum'

Red Bistort | Polygonum amplexicaule 'Atrosanguineum'

Polygonum amplexicaule 'Firetail' is a perennial knotweed that can form mats, clumps or grow tall and upright to about 1.2 metres. Its deciduous leaves are simple, lance- to heart-shaped and are often marked or take on autumn tint. It prefers moist conditions and tolerates a very wide range of soils, including heavy clay, but dislikes drought. Flowering occurs July to September.

Polygonum amplexicaule 'Firetail' is a damp-tolerant perennial to 1.2 metres that flowers July to September and suits most soils, including heavy clay.

Polygonum amplexicaule 'Firetail'

Knotweed | Polygonum amplexicaule 'Firetail'

Polygonum amplexicaule 'Inverleith' is a perennial in the Polygonaceae that can grow as mat-forming or clump-forming plants or as a taller, upright specimen, reaching about 1.2 metres. Leaves are deciduous, simple and range from lance-shaped to heart-shaped, sometimes showing markings or autumn colour. It favours moist conditions and will tolerate heavy clay while disliking drought. Flowering occurs July to September.

Knotweed (Polygonum amplexicaule 'Inverleith') is a deciduous perennial to 1.2 metres that flowers July to September and suits borders and cottage gardens.

Polygonum amplexicaule 'Inverleith'

Knotweed | Polygonum amplexicaule 'Inverleith'

Polygonum amplexicaule oxyphyllum of gardens is a moisture-preferring perennial in the Polygonaceae that can grow as a mat, a clump or a tall, upright plant. Leaves are simple, lance-shaped to heart-shaped, deciduous and often marked or autumn-tinted. It reaches about 1.2 metres and carries summer flower spikes from July to September. Plants suit full sun to partial shade and tolerate almost any soil, including heavy clay, provided the site is not dry.

Knotweed (Polygonum amplexicaule oxyphyllum of gardens) is a moisture-loving perennial from China and the Himalayas that flowers July to September.

Polygonum amplexicaule oxyphyllum of gardens

Knotweed | Polygonum amplexicaule oxyphyllum of gardens

Polygonum bistorta 'Superbum' is a perennial in the family Polygonaceae that flowers from July to September. It reaches about 0.5 m and can form mats, clumps or produce taller, upright flowering stems. Leaves are deciduous, simple and range from lance-shaped to heart-shaped and may take autumn tints. It suits full sun to partial shade and tolerates almost any soil, including heavy clay, provided it is not allowed to dry out.

Knotweed (Polygonum bistorta 'Superbum') flowers July to September and suits moist soils in full sun to partial shade.

https://en.wikipedia.org/wiki/Bistorta_officinalis

Polygonum bistorta 'Superbum'

Knotweed | Polygonum bistorta 'Superbum'

Polygonum campanulatum is a perennial knotweed with a variable habit that can form mats, clumps or grow tall and upright. Leaves are deciduous, simple and range from lance-shaped to heart-shaped, often showing markings or an autumn tint. It tolerates full sun to partial shade and will grow in almost any soil, including heavy clay, provided the ground stays moist. Expect flowering from July to September.

Knotweed (Polygonum campanulatum) is a deciduous perennial from China and the Himalaya that flowers July to September and tolerates damp, clay soils.

https://en.wikipedia.org/wiki/Koenigia_campanulata

Polygonum campanulatum

Knotweed | Polygonum campanulatum

Polygonum carneum is a perennial in the buckwheat family (Polygonaceae) that can grow as a mat-forming ground cover, clump, or a taller upright plant. It has deciduous, simple leaves that range from lance-shaped to heart-shaped and may be marked or take on autumn tints. Flowering occurs from July to September. It suits a wide range of positions and soils, and prefers reliably moist conditions.

Knotweed (Polygonum carneum) flowers from July to September and suits moist, any-soil sites in full sun or partial shade.

Polygonum carneum

Knotweed | Polygonum carneum

Polygonum cuspidatum is a perennial in the Polygonaceae with a variable habit, from mat-forming or clump-forming to tall and upright growth. Leaves are deciduous, simple and range from lance-shaped to heart-shaped, often marked or taking on autumn tints. It tolerates almost any soil, including heavy clay, and favours moist conditions over drought. Flowering occurs July to September.

Japanese knotweed (Polygonum cuspidatum) is a perennial from East Asia that flowers July to September and tolerates most soils, including heavy clay.

https://en.wikipedia.org/wiki/Reynoutria_japonica

Polygonum cuspidatum

Japanese knotweed | Polygonum cuspidatum

Polygonum cuspidatum compactum of gardens is a perennial in the knotweed family with a variable habit that can form mats, clumps or grow more erect. It has deciduous, simple leaves that range from lance-shaped to heart-shaped and are often marked or take on autumn tints. Plants suit full sun to partial shade and prefer reliably moist soil, tolerating heavy clay and a wide pH range. Flowering occurs in the UK from July to September.

Knotweed (Polygonum cuspidatum compactum of gardens) is a deciduous perennial with lance- to heart-shaped leaves and a variable habit, flowering July to.

Polygonum cuspidatum compactum of gardens

Knotweed | Polygonum cuspidatum compactum of gardens

Polygonum equisetiforme is a perennial knotweed that can form mats, clumps or grow upright to about 1.0 m. It has deciduous, simple leaves that range from lance-shaped to heart-shaped and are often marked or take on autumn tints. Flowering occurs July to September. It suits a wide range of sites, including heavy clay and damp ground.

Knotweed (Polygonum equisetiforme) is a perennial from Portugal that reaches about 1.0 m and flowers July to September.

Polygonum equisetiforme

Knotweed | Polygonum equisetiforme

Polygonum milletii is a perennial member of the buckwheat family (Polygonaceae) that can grow as a mat-forming ground cover, clump-forming plant or as a taller upright perennial. The leaves are deciduous, simple and range from lance-shaped to heart-shaped, often showing markings or autumn tint. It flowers from July to September. It tolerates a wide range of soils, including heavy clay, and prefers moist conditions.

Polygonum milletii is a perennial knotweed that flowers July to September and suits moist soil in full sun to partial shade.

Polygonum milletii

Knotweed | Polygonum milletii

Polygonum paniculatum is a perennial member of the buckwheat family (Polygonaceae) with a notably variable habit: it may be mat-forming, clump-forming or grow tall and upright. Leaves are deciduous, simple and range from lance-shaped to heart-shaped, often marked or taking on autumn tint. It prefers full sun to partial shade and tolerates almost any soil, including heavy clay, as long as the ground remains reasonably moist. Flowers are produced from July to September.

Knotweed (Polygonum paniculatum) is a perennial that flowers from July to September and tolerates moist soil and heavy clay.

Polygonum paniculatum

Knotweed | Polygonum paniculatum

Polygonum polystachyum is a perennial in the knotweed family that can be mat-forming, clump-forming or grow tall and upright. Plants reach about 1.8 m and carry deciduous, lance- to heart-shaped leaves that are often marked or turn autumn-tinted. It flowers from July to September. It tolerates full sun to partial shade and a wide range of soils, including heavy clay.

Himalayan knotweed (Polygonum polystachyum) is a Himalayan perennial to about 1.8 m that prefers moist soil in full sun to partial shade.

https://en.wikipedia.org/wiki/Koenigia_polystachya

Polygonum polystachyum

Himalayan knotweed, Cultivated knotweed | Polygonum polystachyum

Polygonum regelianum is a perennial knotweed that shows a notably variable habit, from mat-forming and clump-forming to taller, upright growth. Its deciduous leaves are simple, lance-shaped to heart-shaped and are often marked or take on autumn tints before falling. Flowering occurs July to September. It tolerates a wide range of soils, including heavy clay, and prefers reliably moist conditions over drought.

Knotweed (Polygonum regelianum) is a perennial with variable habit that flowers July to September and suits moist soils in full sun to partial shade.

Polygonum regelianum

Knotweed | Polygonum regelianum

Polygonum rude is a perennial in the knotweed family with a variable habit that can be mat-forming, clump-forming or tall and upright. The foliage is deciduous, simple and ranges from lance-shaped to heart-shaped, often marked or taking on autumn tints. It flowers from July to September. Plants tolerate almost any soil, including heavy clay, and prefer moist conditions in full sun to partial shade.

Knotweed (Polygonum rude) is a deciduous perennial that flowers July to September and thrives in moist soils, tolerating heavy clay in sun or part shade.

Polygonum rude

Knotweed | Polygonum rude

Polygonum sphaerostachyum is a perennial knotweed that may form mats, clumps or grow tall and upright. It has deciduous, simple leaves that range from lance-shaped to heart-shaped and are often marked or take on autumn tints. Flowering occurs July to September. The species tolerates a wide range of soils, including heavy clay, and prefers moist conditions.

Knotweed (Polygonum sphaerostachyum) is a perennial that flowers July to September and tolerates heavy clay and damp soils.

https://en.wikipedia.org/wiki/Bistorta_macrophylla

Polygonum sphaerostachyum

Knotweed | Polygonum sphaerostachyum

Polygonum ussuriense is a perennial knotweed that can be mat-forming, clump-forming or grow tall and upright. Its deciduous leaves are simple, lance- to heart-shaped and are often marked or take on autumn tint. Flowering in the UK occurs from July to September. It tolerates full sun to partial shade and will grow in almost any soil, including heavy clay, provided the ground stays reasonably moist.

Knotweed (Polygonum ussuriense) is a deciduous perennial from northeast Asia that flowers July to September and tolerates heavy clay and moist ground.

Polygonum ussuriense

Knotweed | Polygonum ussuriense

Rheum alexandrae is a perennial in the knotweed family (Polygonaceae) valued for ornamental use in borders and water gardens. It originates from south-west China and flowers in the UK from June to July. Planting and handling require care because all parts are harmful if eaten; wear gloves and protective equipment when working with it.

Alexander's rhubarb (Rheum alexandrae) is a perennial for partial shade and moist, acidic to neutral soils, flowering in the UK from June to July.

Rheum alexandrae

Alexander's rhubarb | Rheum alexandrae

Rheum australe is a perennial herb native to the Himalayas that can reach about 3.0 m in height. It flowers in the UK from June to July. Plant it in full sun on loamy or clay soils that remain moist but drain well. Parts are harmful if eaten, so wear gloves and protective equipment when handling.

Himalayan rhubarb (Rheum australe) is a tall perennial that flowers June to July and prefers full sun on moist, well-drained loamy or clay soil.

https://en.wikipedia.org/wiki/Rheum_australe

Rheum australe

Himalayan rhubarb | Rheum australe

Rheum officinale is a perennial herb in the Polygonaceae that reaches around 2.0 m and produces prominent flowering stems in June to July. It prefers full sun on loamy or clay soils that remain moist but are well drained. Rated H6 (very hardy) it will tolerate typical UK winters across much of the country. Allow generous space for its height when siting it in a border or specimen position.

Chinese Rhubarb (Rheum officinale) is a perennial to 2.0 m that flowers in June–July and prefers full sun with moist, loamy or clay, well-drained soil.

https://en.wikipedia.org/wiki/Rheum_officinale

Rheum officinale

Chinese rhubarb | Rheum officinale

Rheum palmatum is a tall perennial herbaceous plant in the knotweed family that can reach about 3.0 m. It is native to China and Vietnam and flowers in the UK from June to July. Plant in full sun on loamy or clay soils that remain moist but are well drained. Harmful if eaten; wear gloves and other protective equipment when handling.

Chinese rhubarb (Rheum palmatum) is a tall perennial that flowers June to July and suits moist, loamy or clay soils in full sun.

https://en.wikipedia.org/wiki/Rheum_palmatum

Rheum palmatum

Chinese rhubarb | Rheum palmatum

Rheum palmatum 'Atrosanguineum' is a perennial Rheum grown as an architectural, tall-stemmed specimen reaching about 3.0 m. It flowers in June to July and is valued at the back of large borders or as a single focal plant. Originating from China and placed in the Polygonaceae family, it prefers full sun on moist, loamy or clay soils. Wear gloves and other protective equipment when handling, as the plant is harmful if eaten and can be dangerous to pets.

Rhubarb 'Atrosanguineum' is a tall Rheum perennial from China that flowers in June to July and prefers full sun with moist loamy or clay soil.

Rheum palmatum 'Atrosanguineum'

Rhubarb 'Atrosanguineum' | Rheum palmatum 'Atrosanguineum'

Rheum palmatum 'Bowles' Variety' is a perennial in the knotweed family that reaches about 3.0 m and produces tall flowering stems above large palmate leaves. It flowers in June to July, with pink blooms presented on erect panicles. Plant in full sun on loamy or clay soils that remain moist but well-drained and expect it to tolerate UK conditions down to H6 (very hardy).

Rhubarb (Rheum palmatum 'Bowles' Variety') is a perennial to 3.0 m with pink flowers in June–July, best in full sun on moist loamy or clay soils.

Rheum palmatum 'Bowles' Variety'

Rhubarb | Rheum palmatum 'Bowles' Variety'

Rheum palmatum tanguticum is a perennial in the Polygonaceae that reaches about 2.0 m and is cultivated as an ornamental for borders. It flowers in June to July, producing pink blooms above the foliage. Plant in full sun on loamy or clay soil that stays moist but drains freely. Wear gloves and other protective equipment when handling because the plant is harmful if eaten.

Tangut rhubarb (Rheum palmatum tanguticum) is a fully hardy perennial to 2.0 m from China that flowers in June–July and suits sunny, moist loamy or clay.

Rheum palmatum tanguticum

Tangut rhubarb | Rheum palmatum tanguticum

Tovara virginiana is a perennial in the Polygonaceae native to eastern North America that performs reliably in partial shade and shade. It accepts loamy, sandy or clay soils across an acidic to alkaline pH range and prefers moist yet well-drained conditions. Plant on north, east or west aspects in sheltered or semi-exposed spots where it can naturalise in woodland and shade gardens.

Jumpseed (Tovara virginiana) thrives in partial shade on moist, well-drained loamy, sandy or clay soils and suits woodland and shade gardens.

https://en.wikipedia.org/wiki/Persicaria_virginiana

Tovara virginiana

Jumpseed | Tovara virginiana

Tovara virginiana var. filiformis is a perennial in the Polygonaceae notable for seedpods that can 'jump' when disturbed. It is unusually shade-tolerant for a genus that mainly prefers sun and flowers from midsummer into early autumn. Inflorescences are slender stalks of small white to greenish-white flowers. Leaves are larger and more oval than in most related species and can show a chevron-shaped marking on some leaves.

Jumpseed (Tovara virginiana var. filiformis) is a shade-tolerant perennial with midsummer–autumn white flowers and seedpods that 'jump' when disturbed.

Tovara virginiana var. filiformis

Jumpseed | Tovara virginiana var. filiformis

Tovara virginiana var. filiformis 'Painter's Palette' is a shade-tolerant perennial in the Polygonaceae, notable for its slender flowering stalks and seeds that can 'jump' when a ripe pod is disturbed. It flowers from midsummer into early autumn with small white to greenish-white blooms. Leaves are larger and more oval than many relatives and may show chevron-like markings on some leaves. Cultivars and garden selections often differ noticeably from wild plants.

Jumpseed Tovara virginiana var. filiformis 'Painter's Palette' is a shade-tolerant perennial with midsummer white to greenish-white flowers and.

Tovara virginiana var. filiformis 'Painter's Palette'

Jumpseed | Tovara virginiana var. filiformis 'Painter's Palette'

Tovara virginiana var. filiformis 'Variegata' is a shade-tolerant perennial in the Polygonaceae that is noted for the way its ripe seedpods can 'jump' when brushed. It carries small white to greenish-white flowers on slender, wiry stems through mid to late summer. Leaves are relatively large and oval, often with a chevron-shaped marking, and garden selections show more variation than wild plants.

Jumpseed Tovara virginiana var. filiformis 'Variegata' is a shade-tolerant Polygonaceae perennial with small white to greenish-white flowers in mid to.