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Montana Field Guide

Montana Field Guides

Scatter Knotweed - Polygonum spergulariiforme
Other Names:  Polygonum douglasii ssp. spergulariiforme

Status Under Review
Native Species

Global Rank: G5T5
State Rank: SU

Agency Status
MNPS Threat Rank:

External Links

General Description
Stems erect, branched, up to 50 cm tall, usually papillose-scabridulous. Petioles up to 2 mm long. Ochrea 8-12 mm long, cylindrical below but fragmenting into fibers above. Leaves 35-60 long, lanceolate, apex actue or mucronate. Inflorescences lateral or terminal, spike-like, dense, 2-5-flowered. Flowers open or only partially open; perianth 3-5 mm long, tepals oblong-obovate, overlapping, petaloid, pink or white. Achenes 3-5 mm long, black, shiny, smooth to striate-tubercled (adopted from: Costea, Tardif & Hinds, 2005, in Flora N. American Vol. 5).

Range Comments
Native to the Pacific Coast of North America with a few additional records from ID, MT and WY. Montana collections over 100 years old from Yellowstone and Meaghre counties (Kartesz in prep. 2012).

Moist or dry areas (Dorn 2001, Vascular Plants of Wyoming, 3rd Ed.).

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Citation for data on this website:
Scatter Knotweed — Polygonum spergulariiforme.  Montana Field Guide.  .  Retrieved on , from