Species: Polygonum scandens var. scandens L.

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Polygonum scandens var. scandens L.

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TAXONOMY

Family:

Polygonaceae

Genus:

Polygonum

Species Synonyms:

Fallopia scandens (L.) Holub
Bilderdykia scandens (L.) Greene
Polygonum dumetorum var. scandens (L.) Gray
Reynoutria scandens (L.) Shinners
Tiniaria scandens (L.) Small

Common Names:

climbing false buckwheat

DISTRIBUTION

Canada:

southwestern and east-central Saskatchewan – southern Manitoba – Ontario – Quebec – Newfoundland – Nova Scotia

Saskatchewan:

southwestern and east-central Saskatchewan; Cypress Hills - Swift Current, Thunder Hill – Duck Mountain (Bear Head Lake) - Jan Lake

Ecoregion:

Cypress Upland, Mixed Grassland, Aspen Parkland, Boreal Transition, Mid-Boreal Upland, Mid-Boreal Lowland, Churchill River Upland

HABITAT

Saskatchewan:

moist shrubland, open woods, clearings, wet shaded shores, and roadsides

Canada:

damp thickets, clearings, and shores

RARITY STATUS

Provincial Status According
to Harms (2003):

Threatened

Nature Conservancy Status:

G5 S1S2

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Polygonum scandens var. scandens is threatened because it is rare or uncommon in Saskatchewan. No immediate threats are known but may occur in the future.

SPECIES DESCRIPTION

Height:

1 – 5 m long

Stems:

twining, herbaceous, scandent or sprawling, sharply angled, glabrous or papillose, not glaucous

Leaves:

2 – 7, blade 2 – 14 cm long, broadly ovate, base cordate, apex acuminate, scabrid, margin undulate; petiole 0.5 – 10 cm; ocrea usually deciduous, 1 – 6 mm, oblique, tan or brown

Inflorescence:

raceme axillary, 5 – 15 cm, erect or spreading, interrupted, flowers 3 – 6 per ocreole; peduncle 0.1 – 7 cm or absent

Flowers:

tepals 3.8 – 8 mm, green to white or pinkish, glabrous; stamens 8, pubescent proximally; styles connate, stigmas capitate

Fruits:

achenes 3 – 6 mm, dark brown to black, shiny, smooth, wings undulate or crinkled

POLYGONUM KEY FOR SPECIES FOUND IN SASKATCHEWAN

1 Flowers solitary or in small axillary clusters or open racemes; leaves jointed at the base with the petiole, small; outer tepals may be keeled; ocrea often hyaline, 2-lobed	2
1 Flowers in spicate racemes; leaves not jointed at the base with the petiole, large; outer tepals may be winged or unwinged, but not keeled (except in P. cilinode and P. convolvulus); ocrea chartaceous	9

2 Inflorescence compact	3
2 Inflorescence a slender, open raceme	5

3 Achenes black, smooth and shiny; tepals rounded	P. spergulariiforme
3 Achenes yellowish to dark brown, not shiny; tepals pointed	4

4 Bracts definitely white-margined; stems to 20 cm tall	P. polygaloides var. confertiflorum
4 Bracts only slightly white-margined, if at all; stems less than 20 cm	P. polygaloides var. kelloggii

5 Flowers on reflexed pedicels	P. douglasii ssp. douglasii
5 Flowers ascending or spreading	6

6 Achenes shiny; leaves linear to lanceolate	P. ramosissimum
6 Achenes dull; leaves oval	7

7 Perianth bottle-shaped, outer tepal hooded	P. achoreum
7 Perianth not constricted below the apex, outer tepal not hooded	8

8 Leaves on the branches the same size as the ones attached directly to the stem; calyx with greenish-white or pink margins	P. arenastrum (= P. aviculare ssp. depressum)
8 Leaves on the branches much smaller than the ones attached directly to the stem; calyx with white, pink or purple margins	P. aviculare

9 Stems slender and twining; leaves broad, base hastate	10
9 Stems not twining; leaves linear to lanceolate, base not hastate	12

10 Ocrea with a ring of bristles	P. cilinode (= Fallopia cilinodes)
10 Ocrea lacking bristles	11

11 Fruiting calyx to 5 mm long, wings small; plants annual	P. convolvulus var. convolvulus (= Fallopia convolvulus)
11 Fruiting calyx to 1.5 cm long, wings broad; plants perennial	P. scandens var. scandens (= Fallopia scandens)

12 Leaves mainly basal, cauline leaves few and reduced	P. viviparum (= Bistorta vivipara)
12 Leaves mainly cauline, well-developed	13

13 Ocrea with bristles at the summit	14
13 Ocrea without bristles	15

14 Rhizomes forking; perennials; ocrea expanded at the top to create a flange; spikes to 2 cm thick; perianth not glandular	P. amphibium var. stipulaceum (= Persicaria amphibia)
14 Roots fibrous; ocrea not expanded at the top; spikes slender, less than 2 cm thick; perianth glandular	P. punctatum var. confertiflorum (= Persicaria punctata)

15 Annuals, terrestrial; roots fibrous; spikes terminal and axillary, numerous	P. lapathifolium var. lapathifolium (= Persicaria lapathifolia)
15 Perennials, often aquatic; rhizomes forking; spikes terminal, solitary or paired	16

16 Petioles attached near base of ocrea; leaves and upper stems glabrous to sparsely strigose	P. coccineum var. coccineum (= Persicaria amphibia)
16 Petioles attached midway on ocrea; leaves and upper stems densely ashy-gray pubescent	P. coccineum var. pratincola (= Persicaria amphibia)