New York Natural Heritage Program
Small's Knotweed
Polygonum aviculare ssp. buxiforme (Small) Costea & Tardif
Dicots
Polygonum aviculare ssp. buxiforme in flower Kimberly J. Smith
Family: Buckwheat Family (Polygonaceae)

State Protection: Endangered
listed species are those with: 1) 5 or fewer extant sites, or 2) fewer than 1,000 individuals, or 3) restricted to fewer than 4 U.S.G.S. 7 minute topographical maps, or 4) species listed as endangered by U.S. Department of Interior.

Federal Protection: Not Listed

State Rarity Rank: S1
A State Rarity Rank of S1 means: This plant is endangered/critically imperiled in New York because of extreme rarity (typically 5 or fewer populations or very few remaining individuals) or is extremely vulnerable to extirpation from New York due to biological factors.

Global Rarity Rank: G5
A Global Rarity Rank of G5 means: This species is demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.


Did you know?
This plant was formally treated as a full species but the different subspecies of Polygonum aviculare overlap in distinguishing characters and ranges as they have moved into weedy habitats created by humans. The native habitat of this subspecies seems to be beaches and dunes but it is sometimes found in sidewalk cracks, vacant lots, and other weedy places (Flora of North America Editorial Committee 2005).

State Ranking Justification [-]
There are five existing populations but only one of them has more than 100 plants, the rest are very small. There are 17 records from the early 1900s through 1976 which need to be rechecked although one of them is probably gone because of development.

Short-term Trends [-]

Long-term Trends [-]