Smooth Knotweed Persicaria glabra (Willdenow) M. Gomez    Synonyms: Persicaria densiflora, Persicaria portoricensis, Polygonum densiflorum, Polygonum glabrum, Polygonum portoricense.
Kingdom Plantae   >   Division Tracheophyta   >   Class Magnoliopsida   >   Order Caryophyllales   >   Family Polygonaceae   >   Genus Persicaria   


Smooth Knotweed may be found in local floras as either Persicaria glabra or Persicaria densiflora. Some authors consider these synonyms (e.g., Knapp and Naczi 2021) while others separate the two species and recognize Persicaria glabra as an Old World species and Persicaria densiflora as a New World species (e.g., Weakley 2022). Consequently, Weakley (2022) prefers Persicaria densiflora for the species in the Southeast and Maryland.

There are 14 records in the project database.

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Dense-flowered Knotweed in Charles Co., Maryland (9/1/2009). Per Kerry: "It lacks bristles on the ocreae and has these large, forked racemes of flowers." Photo by Kerry Wixted. (MBP list)

Dense-flowered Knotweed blooming in Queen Anne's Co., Maryland (8/25/2013). Photo by Jim Brighton. (MBP list)

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