October 2021 – Guess That Plant
This is the FNJP’s 127th edition of Guess that Plant!
The October Guess that Plant fis a photo taken under a stereoscpe. The photo captures caryopsis characters needed to identify this grass Think you know this plant? If so, send your answer for this month’s Guess that Plant.
Persicaria lapathifolium (L) Delarbre; Pale or Nodding Knotweed
The September Guess that Plant is an facultative native wetland annual common to New Jersey’s disturbed habitats. This smartweed is also known as pale or culrytop knotweed. Its synonym binomial is Polygonum lapathifolium. The genus is identified in the smartweed family, the Polygonaceae. Nodding knotweed is distinguished from other smartweeds by its large stature, often reach more than a meter in height. It has dropping flower spikes, and the flowers are a pale pink color. As the common names indicate, the inflorescence droops, providing the nodding effect. Mary Hough (1983) maps the species through Northern New Jersey, with few south county collections. My southern New Jersey observations has identified the species in all seven Coastal Plain counties. The western Native American tribes used the plant for a medicine, food and fiber.