Polygonum polygaloides ssp. confertiflorum (White-Margined Knotweed) - photos and description


Clump of many plants.


Clump of many plants.


Bracts of the inflorescence with white margins.


Flowers are axillary. 


Leaves linear.


Looking straight down on a clump of these tiny plants. 

General: Tiny annual with a simple or branched growth habit, recognizable by its white-margined bracts. Plants glabrous. Lower stems and leaves sometimes red-coloured.

Flowers: Flowers crowded around top of stem in leaf axils. Flowers greenish-white, we measured a flower at 2 mm diameter. Bracts are linear lanceolate with a conspicuous white margin, leaf-like. We measured a bract at 5 mm long by 1 mm wide.

Leaves:  Leaves alternate, linear, we measured a stem leaf at 10 mm long by 1 mm wide.

Height: Height listed in Budd's Flora to 15 cm, we measured plants to 6.5 cm tall.

Habitat: Moist meadows and flats.

Abundance: Very rare, ranked as an S2 by the Saskatchewan Conservation Data Centre.

Origin: Native.

Synonym: Listed in some of the books we use as P. confertiflorum, and, P. watsonii.

How to identify this species of Polygonum: Annual, terminal spikes, bracts white-edged (Taxonomic Reminder for Recognizing Saskatchewan Plants).

When and where photographed: Took the above photos June 23rd, grassy, dried stream bed in prairie pasture, Cypress Hills, about 400 km southwest of our home in Regina, SK.