| Author | | |
| Distribution | Across the state, with no large gaps. Possibly occurs in every county.
Native of Eurasia; in N.A. throughout. | |
| Abundance | Frequent to common throughout. Not yet known from the Outer Banks. | |
| Habitat | Disturbed places, waste places, lawns, farms, barnyards, railroad margins, roadsides, sidewalk cracks, vacant lots. | |
| Phenology | Flowering and fruiting March-November. | |
| Identification | Prostrate Knotweed is the Poster Child of a weed -- it looks like one, acts like one, grows in highly disturbed places, and not loved by anyone. The plants are prostrate to ascending (some forms may be rather erect), much branched; the leaves are narrowly lance-shaped and gray-green or plain green. Fresh ocreae (collars at the junction of the stem and leafstalk) are silvery but soon shred into fibers. The inflorescences are inconspicuous, axillary and terminal. FNA has excellent texts and maps of the various subspecies, with a key. P. glaucum of ocean beaches is a much bigger plant (but still prostrate), brighter gray-green or blue-green, and the silvery tips of the ocreae are persistent. | |
| Taxonomic Comments | Weakley (2018) and FNA (2005) recognize several subspecies; some of these have been treated as full species by other authors. For convenience we unite them all here.
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| Other Common Name(s) | | |
| State Rank | SE | |
| Global Rank | GNR | |
| State Status | | |
| US Status | | |
| USACE-agcp | FAC link |
| USACE-emp | FACU link |
